8.1
HIGH CVSS 3.1
CVE-2026-0891
Memory safety bugs fixed in Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147
Description

Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.

INFO

Published Date :

Jan. 13, 2026, 2:16 p.m.

Last Modified :

July 15, 2026, 2:17 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-0891 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Mozilla firefox
2 Mozilla firefox_esr
3 Mozilla thunderbird
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Solution
Update affected Firefox and Thunderbird products to the latest versions to fix memory corruption bugs.
  • Update Firefox to version 147 or later.
  • Update Firefox ESR to version 140.7 or later.
  • Update Thunderbird to version 147 or later.
  • Update Thunderbird ESR to version 140.7 or later.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-0891.

URL Resource
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1964722%2C2000981%2C2003100%2C2003278 Broken Link
https://www.mozilla.org/security/advisories/mfsa2026-01/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-03/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-04/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-05/ Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:0667
https://access.redhat.com/errata/RHSA-2026:0694
https://access.redhat.com/errata/RHSA-2026:0924
https://access.redhat.com/errata/RHSA-2026:1320
https://access.redhat.com/errata/RHSA-2026:1413
https://access.redhat.com/errata/RHSA-2026:1414
https://access.redhat.com/errata/RHSA-2026:1415
https://access.redhat.com/errata/RHSA-2026:1461
https://access.redhat.com/errata/RHSA-2026:1462
https://access.redhat.com/errata/RHSA-2026:1471
https://access.redhat.com/errata/RHSA-2026:1487
https://access.redhat.com/errata/RHSA-2026:2041
https://access.redhat.com/errata/RHSA-2026:2043
https://access.redhat.com/errata/RHSA-2026:2044
https://access.redhat.com/errata/RHSA-2026:2047
https://access.redhat.com/errata/RHSA-2026:2069
https://access.redhat.com/errata/RHSA-2026:2070
https://access.redhat.com/errata/RHSA-2026:2073
https://access.redhat.com/errata/RHSA-2026:2074
https://access.redhat.com/errata/RHSA-2026:2220
https://access.redhat.com/errata/RHSA-2026:2231
https://access.redhat.com/errata/RHSA-2026:2271
https://access.redhat.com/errata/RHSA-2026:2286
https://access.redhat.com/security/cve/CVE-2026-0891
https://bugzilla.redhat.com/show_bug.cgi?id=2428963
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0891.json
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-0891 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-0891 vulnerability anywhere in the article.

  • CybersecurityNews
Firefox 147 Released With Fixes for 16 Vulnerabilities that Enable Arbitrary Code Execution

Mozilla released Firefox 147 on January 13, 2026, addressing 16 security vulnerabilities detailed in the Mozilla Foundation Security Advisory. The update patches critical issues across components such ... Read more

Published Date: Jan 15, 2026 (6 months ago)

The following table lists the changes that have been made to the CVE-2026-0891 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    Jul. 15, 2026

    Action Type Old Value New Value
    Changed Affected [{'cpes': ['cpe:/o:redhat:rhel_els:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux Server (v. 7 ELS)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux_eus:10.0'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v. 10.0)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10.1'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 10)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.2::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream AUS (v. 8.2)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.4::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream AUS (v.8.4)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus_long_life:8.4::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream AUS (v.8.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:8.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream E4S (v.8.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_tus:8.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream TUS (v.8.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:8.8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream E4S (v.8.8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_tus:8.8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream TUS (v.8.8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:9.0::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream E4S (v.9.0)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:9.2::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream E4S (v.9.2)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.4::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v.9.4)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v.9.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 9)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 6', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 7', 'defaultStatus': 'affected'}] [{'cpes': ['cpe:/o:redhat:enterprise_linux:10.1'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el10_1', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10.1'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el10_1', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux_eus:10.0'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10.0 Extended Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el10_0', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux_eus:10.0'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10.0 Extended Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el10_0', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:rhel_els:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 7 Extended Lifecycle Support', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el7_9', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_10', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_10', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.2 Advanced Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_2', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.2 Advanced Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_2', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.4'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_4', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.4'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_4', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus_long_life:8.4'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_4', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus_long_life:8.4'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_4', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_tus:8.6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.6 Telecommunications Update Service', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_tus:8.6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.6 Telecommunications Update Service', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:8.6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:8.6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_tus:8.8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.8 Telecommunications Update Service', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_8', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_tus:8.8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.8 Telecommunications Update Service', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_8', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:8.8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_8', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:8.8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el8_8', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el9_7', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el9_7', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:9.0'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el9_0', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:9.0'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el9_0', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:9.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el9_2', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:9.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el9_2', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.4'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9.4 Extended Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el9_4', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.4'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9.4 Extended Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el9_4', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9.6 Extended Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-2.el9_6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9.6 Extended Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.7.0-1.el9_6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10', 'packageName': 'rhel10/firefox-flatpak', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10', 'packageName': 'rhel10/thunderbird-flatpak', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 6', 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unknown'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 6', 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unknown'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 7', 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unknown'}]
  • CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    Jun. 30, 2026

    Action Type Old Value New Value
    Added Affected [{'cpes': ['cpe:/o:redhat:rhel_els:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux Server (v. 7 ELS)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux_eus:10.0'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v. 10.0)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10.1'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 10)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.2::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream AUS (v. 8.2)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.4::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream AUS (v.8.4)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus_long_life:8.4::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream AUS (v.8.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:8.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream E4S (v.8.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_tus:8.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream TUS (v.8.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:8.8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream E4S (v.8.8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_tus:8.8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream TUS (v.8.8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:9.0::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream E4S (v.9.0)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:9.2::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream E4S (v.9.2)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.4::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v.9.4)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v.9.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 9)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 6', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 7', 'defaultStatus': 'affected'}]
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
    Added Reference https://access.redhat.com/errata/RHSA-2026:0667
    Added Reference https://access.redhat.com/errata/RHSA-2026:0694
    Added Reference https://access.redhat.com/errata/RHSA-2026:0924
    Added Reference https://access.redhat.com/errata/RHSA-2026:1320
    Added Reference https://access.redhat.com/errata/RHSA-2026:1413
    Added Reference https://access.redhat.com/errata/RHSA-2026:1414
    Added Reference https://access.redhat.com/errata/RHSA-2026:1415
    Added Reference https://access.redhat.com/errata/RHSA-2026:1461
    Added Reference https://access.redhat.com/errata/RHSA-2026:1462
    Added Reference https://access.redhat.com/errata/RHSA-2026:1471
    Added Reference https://access.redhat.com/errata/RHSA-2026:1487
    Added Reference https://access.redhat.com/errata/RHSA-2026:2041
    Added Reference https://access.redhat.com/errata/RHSA-2026:2043
    Added Reference https://access.redhat.com/errata/RHSA-2026:2044
    Added Reference https://access.redhat.com/errata/RHSA-2026:2047
    Added Reference https://access.redhat.com/errata/RHSA-2026:2069
    Added Reference https://access.redhat.com/errata/RHSA-2026:2070
    Added Reference https://access.redhat.com/errata/RHSA-2026:2073
    Added Reference https://access.redhat.com/errata/RHSA-2026:2074
    Added Reference https://access.redhat.com/errata/RHSA-2026:2220
    Added Reference https://access.redhat.com/errata/RHSA-2026:2231
    Added Reference https://access.redhat.com/errata/RHSA-2026:2271
    Added Reference https://access.redhat.com/errata/RHSA-2026:2286
    Added Reference https://access.redhat.com/security/cve/CVE-2026-0891
    Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2428963
    Added Reference https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0891.json
  • CVE Modified by [email protected]

    Jun. 17, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'Mozilla', 'product': 'Firefox', 'versions': [{'status': 'unaffected', 'version': '140.7', 'versionType': 'rpm', 'lessThanOrEqual': '140.*'}, {'status': 'unaffected', 'version': '147', 'versionType': 'rpm', 'lessThanOrEqual': '*'}]}, {'vendor': 'Mozilla', 'product': 'Thunderbird', 'versions': [{'status': 'unaffected', 'version': '140.7', 'versionType': 'rpm', 'lessThanOrEqual': '140.*'}, {'status': 'unaffected', 'version': '147', 'versionType': 'rpm', 'lessThanOrEqual': '*'}]}]
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jun. 17, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-0891', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-01-15T04:56:05.302771Z'}
  • CVE Modified by [email protected]

    Apr. 13, 2026

    Action Type Old Value New Value
    Changed Description Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 147, Firefox ESR < 140.7, Thunderbird < 147, and Thunderbird < 140.7. Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
  • Initial Analysis by [email protected]

    Jan. 22, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* versions up to (excluding) 147.0 *cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* versions up to (excluding) 140.7.0 *cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:* versions up to (excluding) 147.0 *cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* versions up to (excluding) 140.7.0
    Added Reference Type Mozilla Corporation: https://bugzilla.mozilla.org/buglist.cgi?bug_id=1964722%2C2000981%2C2003100%2C2003278 Types: Broken Link
    Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-01/ Types: Vendor Advisory
    Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-03/ Types: Vendor Advisory
    Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-04/ Types: Vendor Advisory
    Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-05/ Types: Vendor Advisory
  • CVE Modified by [email protected]

    Jan. 15, 2026

    Action Type Old Value New Value
    Changed Description Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 147 and Firefox ESR < 140.7. Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 147, Firefox ESR < 140.7, Thunderbird < 147, and Thunderbird < 140.7.
    Added Reference https://www.mozilla.org/security/advisories/mfsa2026-04/
    Added Reference https://www.mozilla.org/security/advisories/mfsa2026-05/
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jan. 13, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-119
  • New CVE Received by [email protected]

    Jan. 13, 2026

    Action Type Old Value New Value
    Added Description Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 147 and Firefox ESR < 140.7.
    Added Reference https://bugzilla.mozilla.org/buglist.cgi?bug_id=1964722%2C2000981%2C2003100%2C2003278
    Added Reference https://www.mozilla.org/security/advisories/mfsa2026-01/
    Added Reference https://www.mozilla.org/security/advisories/mfsa2026-03/
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.