8.2
HIGH
CVSS 3.1
CVE-2026-4371
Out of bounds read in IMAP parsing
Overview
Description
A malicious mail server could send malformed strings with negative lengths, causing the parser to read memory outside the buffer. If a mail server or connection to a mail server were compromised, an attacker could cause the parser to malfunction, potentially crashing Thunderbird or leaking sensitive data. This vulnerability was fixed in Thunderbird 149 and Thunderbird 140.9.
Details
INFO
Published Date :
March 24, 2026, 9:16 p.m.
Last Modified :
July 15, 2026, 2:22 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
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 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | ||||
| CVSS 3.1 | HIGH | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c |
Solution
Update Thunderbird to resolve memory corruption issues potentially leading to crashes or data leaks.
- Update Thunderbird to version 149 or later.
- Update Thunderbird to version 140.9 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-2026-4371.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-4371 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-2026-4371
weaknesses.
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-2026-4371 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-4371 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: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': '0:140.9.0-1.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': '0:140.9.0-1.el10_0', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', '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': '0:140.9.0-1.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': '0:140.9.0-1.el8_2', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.4'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.9.0-1.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': '0:140.9.0-1.el8_4', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_aus:8.6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.9.0-1.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': '0:140.9.0-1.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': '0:140.9.0-1.el8_6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_tus:8.8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8.8 Telecommunications Update Service', 'versions': [{'status': 'unaffected', 'version': '0:140.9.0-1.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': '0:140.9.0-1.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': '0:140.9.0-1.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': '0:140.9.0-1.el9_0', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_e4s:9.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions', 'versions': [{'status': 'unaffected', 'version': '0:140.9.0-1.el9_2', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.4'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9.4 Extended Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.9.0-1.el9_4', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9.6 Extended Update Support', 'versions': [{'status': 'unaffected', 'version': '0:140.9.0-1.el9_6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'thunderbird', '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': '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: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:N/S:U/C:L/I:N/A:H Added CWE CWE-130 Added Reference https://access.redhat.com/errata/RHSA-2026:6188 Added Reference https://access.redhat.com/errata/RHSA-2026:6342 Added Reference https://access.redhat.com/errata/RHSA-2026:6917 Added Reference https://access.redhat.com/errata/RHSA-2026:8284 Added Reference https://access.redhat.com/errata/RHSA-2026:8285 Added Reference https://access.redhat.com/errata/RHSA-2026:8286 Added Reference https://access.redhat.com/errata/RHSA-2026:8287 Added Reference https://access.redhat.com/errata/RHSA-2026:8288 Added Reference https://access.redhat.com/errata/RHSA-2026:8289 Added Reference https://access.redhat.com/errata/RHSA-2026:8290 Added Reference https://access.redhat.com/errata/RHSA-2026:8315 Added Reference https://access.redhat.com/errata/RHSA-2026:8850 Added Reference https://access.redhat.com/security/cve/CVE-2026-4371 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2451001 Added Reference https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4371.json -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Mozilla', 'product': 'Thunderbird', 'versions': [{'status': 'unaffected', 'version': '140.9', 'versionType': 'rpm', 'lessThanOrEqual': '140.*'}, {'status': 'unaffected', 'version': '149', 'versionType': 'rpm', 'lessThanOrEqual': '*'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-4371', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-03-25T16:24:48.052212Z'} -
CVE Modified by [email protected]
Apr. 13, 2026
Action Type Old Value New Value Changed Description A malicious mail server could send malformed strings with negative lengths, causing the parser to read memory outside the buffer. If a mail server or connection to a mail server were compromised, an attacker could cause the parser to malfunction, potentially crashing Thunderbird or leaking sensitive data. This vulnerability affects Thunderbird < 149 and Thunderbird < 140.9. A malicious mail server could send malformed strings with negative lengths, causing the parser to read memory outside the buffer. If a mail server or connection to a mail server were compromised, an attacker could cause the parser to malfunction, potentially crashing Thunderbird or leaking sensitive data. This vulnerability was fixed in Thunderbird 149 and Thunderbird 140.9. -
Initial Analysis by [email protected]
Mar. 27, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:* versions up to (excluding) 149.0 *cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* versions up to (excluding) 140.9.0 Added Reference Type Mozilla Corporation: https://bugzilla.mozilla.org/show_bug.cgi?id=2023493 Types: Permissions Required Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-23/ Types: Vendor Advisory Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-24/ Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Mar. 25, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H Added CWE CWE-126 -
New CVE Received by [email protected]
Mar. 24, 2026
Action Type Old Value New Value Added Description A malicious mail server could send malformed strings with negative lengths, causing the parser to read memory outside the buffer. If a mail server or connection to a mail server were compromised, an attacker could cause the parser to malfunction, potentially crashing Thunderbird or leaking sensitive data. This vulnerability affects Thunderbird < 149 and Thunderbird < 140.9. Added Reference https://bugzilla.mozilla.org/show_bug.cgi?id=2023493 Added Reference https://www.mozilla.org/security/advisories/mfsa2026-23/ Added Reference https://www.mozilla.org/security/advisories/mfsa2026-24/
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.