VulnerabilityModified
CVE-2025-5269
This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code.
HIGH 8.1EPSS 0.46%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Memory safety bug present in Firefox ESR 128.10, and Thunderbird 128.10. 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 ESR 128.11 and Thunderbird 128.11.
- CVSS 3.1
- 8.1 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.46% probability · 39th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1924108Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2025-44/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-46/
- https://lists.debian.org/debian-lts-announce/2025/05/msg00043.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.