Memory Safety Vulnerabilities in Firefox ESR and Firefox Products
CVE-2026-16412

9.8CRITICAL

Key Information:

Vendor

Mozilla
Status
Firefox
Thunderbird
Vendor
CVE Published:
21 July 2026

What is CVE-2026-16412?

Mozilla Firefox ESR version 140.12 and Firefox version 152 contain memory safety bugs that could lead to memory corruption. If successfully exploited, these vulnerabilities might allow an attacker to execute arbitrary code on the affected systems. Mozilla has addressed these issues in Firefox version 153 and Firefox ESR version 140.13, providing users with important security updates to mitigate these risks.

Affected Version(s)

Firefox 140.13

Firefox 153

Thunderbird 140.13

References

https://bugzilla.mozilla.org/buglist.cgi?bug_id=2005113%2...
https://bugzilla.mozilla.org/buglist.cgi?bug_id=2043035%2...
https://bugzilla.mozilla.org/buglist.cgi?bug_id=2045413%2...

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Christian Holler, Frederik Braun, Justin Link, Simon Friedberger, Tom Ritter, Tom Schuster and the Mozilla Fuzzing Team
.