Memory Safety Vulnerability in Firefox and Thunderbird by Mozilla
CVE-2025-11721

9.8CRITICAL

Key Information:

Vendor

Mozilla
Status
Firefox
Thunderbird
Vendor
CVE Published:
14 October 2025

What is CVE-2025-11721?

A memory safety bug found in Firefox versions prior to 144 and Thunderbird versions prior to 144 may lead to memory corruption. Given sufficient effort, this vulnerability could potentially be exploited to execute arbitrary code, placing users at risk. Mozilla has addressed this issue in the latest versions, underscoring the importance of keeping software up-to-date to mitigate security risks.

Affected Version(s)

Firefox < 144

Thunderbird < 144

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1986816
https://www.mozilla.org/security/advisories/mfsa2025-81/
https://www.mozilla.org/security/advisories/mfsa2025-84/

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

JSON
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