CVE-2025-11721: Memory safety bug fixed in Firefox 144 and Thunderbird 144
Memory safety bug present in Firefox 143 and Thunderbird 143. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 144 and Thunderbird 144.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 144 - Upgrade
Upgrade
debian/firefoxto a version that resolves this vulnerability.Fixed in 159.0-1 - Upgrade
Upgrade
Firefoxto a version that resolves this vulnerability.Fixed in 144 - Upgrade
Upgrade
Thunderbirdto a version that resolves this vulnerability.Fixed in 144
Event History
Peer vulnerabilities
Found alongside the following vulnerabilities.
Frequently Asked Questions
What is the severity of CVE-2025-11721?
CVE-2025-11721 is a memory safety vulnerability that could potentially allow for arbitrary code execution.
How do I fix CVE-2025-11721?
To mitigate CVE-2025-11721, users should upgrade to Firefox or Thunderbird version 144 or later.
Which software is affected by CVE-2025-11721?
CVE-2025-11721 affects Mozilla Firefox and Thunderbird versions prior to 144.
What type of vulnerability is CVE-2025-11721?
CVE-2025-11721 is classified as a memory safety bug.
Is there any evidence of exploitation for CVE-2025-11721?
CVE-2025-11721 shows evidence of memory corruption, suggesting a potential pathway for exploitation.