9.8
CRITICAL
CVSS 3.1
CVE-2026-5734
Memory safety bugs fixed in Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2
Overview
Description
Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. 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 149.0.2, Firefox ESR 140.9.1, Thunderbird 149.0.2, and Thunderbird 140.9.1.
Details
INFO
Published Date :
April 7, 2026, 1:16 p.m.
Last Modified :
July 15, 2026, 1:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Impact
Affected Products
The following products are affected by CVE-2026-5734
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.
Scoring
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 | CRITICAL | [email protected] | ||||
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | ||||
| CVSS 3.1 | HIGH | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c |
Solution
Update affected software to patch memory corruption vulnerabilities and prevent arbitrary code execution.
- Update Firefox ESR to version 140.9.1 or later.
- Update Firefox to version 149.0.2 or later.
- Update Thunderbird ESR to version 140.9.1 or later.
- Update Thunderbird to version 149.0.2 or later.
References
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-2026-5734.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-5734 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-5734
weaknesses.
CAPEC-8: Buffer Overflow in an API Call Buffer Overflow in an API Call
CAPEC-9: Buffer Overflow in Local Command-Line Utilities Buffer Overflow in Local Command-Line Utilities
CAPEC-10: Buffer Overflow via Environment Variables Buffer Overflow via Environment Variables
CAPEC-14: Client-side Injection-induced Buffer Overflow Client-side Injection-induced Buffer Overflow
CAPEC-24: Filter Failure through Buffer Overflow Filter Failure through Buffer Overflow
CAPEC-42: MIME Conversion MIME Conversion
CAPEC-44: Overflow Binary Resource File Overflow Binary Resource File
CAPEC-45: Buffer Overflow via Symbolic Links Buffer Overflow via Symbolic Links
CAPEC-46: Overflow Variables and Tags Overflow Variables and Tags
CAPEC-47: Buffer Overflow via Parameter Expansion Buffer Overflow via Parameter Expansion
CAPEC-67: String Format Overflow in syslog() String Format Overflow in syslog()
CAPEC-92: Forced Integer Overflow Forced Integer Overflow
CAPEC-100: Overflow Buffers Overflow Buffers
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-2026-5734 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-5734 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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.el10_0', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', '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': '0:140.9.1-1.el10_0', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', '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': '0:140.9.1-2.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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.el8_4', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'firefox', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.4'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.el8_4', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.9.1-1.el8_6', '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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.el8_6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_tus:8.8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.8 Telecommunications Update Service', 'versions': [{'status': 'unaffected', 'version': '0:140.9.1-1.el8_8', '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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.el8_8', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', '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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.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': '0:140.9.1-1.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:L/PR:N/UI:R/S:U/C:H/I:H/A:H Added CWE CWE-787 Added Reference https://access.redhat.com/errata/RHSA-2026:11805 Added Reference https://access.redhat.com/errata/RHSA-2026:11813 Added Reference https://access.redhat.com/errata/RHSA-2026:12264 Added Reference https://access.redhat.com/errata/RHSA-2026:13342 Added Reference https://access.redhat.com/errata/RHSA-2026:13412 Added Reference https://access.redhat.com/errata/RHSA-2026:13533 Added Reference https://access.redhat.com/errata/RHSA-2026:13582 Added Reference https://access.redhat.com/errata/RHSA-2026:13583 Added Reference https://access.redhat.com/errata/RHSA-2026:13596 Added Reference https://access.redhat.com/errata/RHSA-2026:13600 Added Reference https://access.redhat.com/errata/RHSA-2026:13665 Added Reference https://access.redhat.com/errata/RHSA-2026:13682 Added Reference https://access.redhat.com/errata/RHSA-2026:13683 Added Reference https://access.redhat.com/errata/RHSA-2026:13922 Added Reference https://access.redhat.com/errata/RHSA-2026:13977 Added Reference https://access.redhat.com/errata/RHSA-2026:14223 Added Reference https://access.redhat.com/errata/RHSA-2026:14303 Added Reference https://access.redhat.com/errata/RHSA-2026:15889 Added Reference https://access.redhat.com/errata/RHSA-2026:7671 Added Reference https://access.redhat.com/errata/RHSA-2026:7672 Added Reference https://access.redhat.com/errata/RHSA-2026:8052 Added Reference https://access.redhat.com/errata/RHSA-2026:8459 Added Reference https://access.redhat.com/errata/RHSA-2026:9345 Added Reference https://access.redhat.com/errata/RHSA-2026:9638 Added Reference https://access.redhat.com/security/cve/CVE-2026-5734 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2455897 Added Reference https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-5734.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': '140.9.1', 'versionType': 'rpm', 'lessThanOrEqual': '140.*'}, {'status': 'unaffected', 'version': '149.0.2', 'versionType': 'rpm', 'lessThanOrEqual': '*'}]}, {'vendor': 'Mozilla', 'product': 'Thunderbird', 'versions': [{'status': 'unaffected', 'version': '140.9.1', 'versionType': 'rpm', 'lessThanOrEqual': '140.*'}, {'status': 'unaffected', 'version': '149.0.2', 'versionType': 'rpm', 'lessThanOrEqual': '*'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-5734', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-04-08T03:55:30.963374Z'} -
CVE Modified by [email protected]
Apr. 13, 2026
Action Type Old Value New Value Changed Description Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. 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 < 149.0.2, Firefox ESR < 140.9.1, Thunderbird < 149.0.2, and Thunderbird < 140.9.1. Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. 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 149.0.2, Firefox ESR 140.9.1, Thunderbird 149.0.2, and Thunderbird 140.9.1. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Apr. 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-120 -
CVE Modified by [email protected]
Apr. 07, 2026
Action Type Old Value New Value Changed Description Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. 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 < 149.0.2 and Firefox ESR < 140.9.1. Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. 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 < 149.0.2, Firefox ESR < 140.9.1, Thunderbird < 149.0.2, and Thunderbird < 140.9.1. Added Reference https://www.mozilla.org/security/advisories/mfsa2026-28/ Added Reference https://www.mozilla.org/security/advisories/mfsa2026-29/ -
Initial Analysis by [email protected]
Apr. 07, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-787 Added CPE Configuration OR *cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* versions up to (excluding) 149.0.2 *cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* versions up to (excluding) 140.9.1 *cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:* versions up to (excluding) 149.0.2 *cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* versions up to (excluding) 140.9.1 Added Reference Type Mozilla Corporation: https://bugzilla.mozilla.org/buglist.cgi?bug_id=2022369%2C2023026%2C2023545%2C2023555%2C2023958%2C2025422%2C2025468%2C2025492%2C2025505 Types: Broken Link, Issue Tracking Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-25/ Types: Vendor Advisory Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-27/ Types: Vendor Advisory -
New CVE Received by [email protected]
Apr. 07, 2026
Action Type Old Value New Value Added Description Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. 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 < 149.0.2 and Firefox ESR < 140.9.1. Added Reference https://bugzilla.mozilla.org/buglist.cgi?bug_id=2022369%2C2023026%2C2023545%2C2023555%2C2023958%2C2025422%2C2025468%2C2025492%2C2025505 Added Reference https://www.mozilla.org/security/advisories/mfsa2026-25/ Added Reference https://www.mozilla.org/security/advisories/mfsa2026-27/
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.