CVE-2025-3030

Memory safety bugs present in Firefox 136, Thunderbird 136, Firefox ESR 128.8, and Thunderbird 128.8. 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 affects Firefox < 137, Firefox ESR < 128.9, Thunderbird < 137, and Thunderbird < 128.9.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://bugzilla.mozilla.org/buglist.cgi?bug_id=1850615%2C1932468%2C1942551%2C1951017%2C1951494
• https://www.mozilla.org/security/advisories/mfsa2025-20/
• https://www.mozilla.org/security/advisories/mfsa2025-22/
• https://www.mozilla.org/security/advisories/mfsa2025-23/
• https://www.mozilla.org/security/advisories/mfsa2025-24/