9.8
CRITICAL CVSS 3.1
CVE-2026-16412
Memory safety bugs fixed in Firefox ESR 140.13 and Firefox 153
Description

Memory safety bugs present in Firefox ESR 140.12 and Firefox 152. 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 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

INFO

Published Date :

July 21, 2026, 1:17 p.m.

Last Modified :

July 24, 2026, 5:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-16412 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 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 CRITICAL 134c704f-9b21-4f2e-91b3-4a467353bcc0
Solution
Update Firefox ESR to 140.13 or Firefox to 153 to fix memory corruption vulnerabilities.
  • Update Firefox ESR to version 140.13.
  • Update Firefox to version 153.
  • Apply vendor patches when available.
  • Restart the application after updates.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-16412 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-2026-16412 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-16412 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 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 24, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-16412', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-21T19:13:15.778832Z'} {'id': 'CVE-2026-16412', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-23T00:00:00+00:00'}
  • CVE Modified by [email protected]

    Jul. 23, 2026

    Action Type Old Value New Value
    Changed Description Memory safety bugs present in Thunderbird ESR 140.12 and Thunderbird 152. 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 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13. Memory safety bugs present in Firefox ESR 140.12 and Firefox 152. 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 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
  • CVE Modified by [email protected]

    Jul. 22, 2026

    Action Type Old Value New Value
    Changed Affected [{'vendor': 'Mozilla', 'product': 'Firefox', 'versions': [{'status': 'unaffected', 'version': '140.13', 'versionType': 'rpm', 'lessThanOrEqual': '140.*'}, {'status': 'unaffected', 'version': '153', 'versionType': 'rpm', 'lessThanOrEqual': '*'}]}] [{'vendor': 'Mozilla', 'product': 'Firefox', 'versions': [{'status': 'unaffected', 'version': '140.13', 'versionType': 'rpm', 'lessThanOrEqual': '140.*'}, {'status': 'unaffected', 'version': '153', 'versionType': 'rpm', 'lessThanOrEqual': '*'}]}, {'vendor': 'Mozilla', 'product': 'Thunderbird', 'versions': [{'status': 'unaffected', 'version': '140.13', 'versionType': 'rpm', 'lessThanOrEqual': '140.*'}, {'status': 'unaffected', 'version': '153', 'versionType': 'rpm', 'lessThanOrEqual': '*'}]}]
    Changed Description Memory safety bugs present in Firefox ESR 140.12 and Firefox 152. 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 153 and Firefox ESR 140.13. Memory safety bugs present in Thunderbird ESR 140.12 and Thunderbird 152. 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 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
    Added Reference https://www.mozilla.org/security/advisories/mfsa2026-71/
    Added Reference https://www.mozilla.org/security/advisories/mfsa2026-72/
  • Initial Analysis by [email protected]

    Jul. 22, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* versions up to (excluding) 153.0.0 *cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* versions from (including) 140.1.0 up to (excluding) 140.13.0
    Added Reference Type Mozilla Corporation: https://bugzilla.mozilla.org/buglist.cgi?bug_id=2005113%2C2025369%2C2026301%2C2028663%2C2029761%2C2042242%2C2043271%2C2043300%2C2044612%2C2045378%2C2045406%2C2045407%2C2045616%2C2045626%2C2045730%2C2045732%2C2045769%2C2045771%2C2047957%2C2048934%2C2049818%2C2049822%2C2050151%2C2050368%2C2051653%2C2051658 Types: Broken Link
    Added Reference Type Mozilla Corporation: https://bugzilla.mozilla.org/buglist.cgi?bug_id=2043035%2C2045057%2C2045187%2C2045402%2C2045417%2C2045482%2C2045611%2C2045618%2C2045756%2C2046917%2C2047718 Types: Broken Link
    Added Reference Type Mozilla Corporation: https://bugzilla.mozilla.org/buglist.cgi?bug_id=2045413%2C2053635%2C2053637 Types: Broken Link
    Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-68/ Types: Vendor Advisory
    Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-70/ Types: Vendor Advisory
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 21, 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-119
    Added SSVC {'id': 'CVE-2026-16412', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-21T19:13:15.778832Z'}
  • New CVE Received by [email protected]

    Jul. 21, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'Mozilla', 'product': 'Firefox', 'versions': [{'status': 'unaffected', 'version': '140.13', 'versionType': 'rpm', 'lessThanOrEqual': '140.*'}, {'status': 'unaffected', 'version': '153', 'versionType': 'rpm', 'lessThanOrEqual': '*'}]}]
    Added Description Memory safety bugs present in Firefox ESR 140.12 and Firefox 152. 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 153 and Firefox ESR 140.13.
    Added Reference https://bugzilla.mozilla.org/buglist.cgi?bug_id=2005113%2C2025369%2C2026301%2C2028663%2C2029761%2C2042242%2C2043271%2C2043300%2C2044612%2C2045378%2C2045406%2C2045407%2C2045616%2C2045626%2C2045730%2C2045732%2C2045769%2C2045771%2C2047957%2C2048934%2C2049818%2C2049822%2C2050151%2C2050368%2C2051653%2C2051658
    Added Reference https://bugzilla.mozilla.org/buglist.cgi?bug_id=2043035%2C2045057%2C2045187%2C2045402%2C2045417%2C2045482%2C2045611%2C2045618%2C2045756%2C2046917%2C2047718
    Added Reference https://bugzilla.mozilla.org/buglist.cgi?bug_id=2045413%2C2053635%2C2053637
    Added Reference https://www.mozilla.org/security/advisories/mfsa2026-68/
    Added Reference https://www.mozilla.org/security/advisories/mfsa2026-70/
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.