CVE-2025-0243
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.
Does this matter?
Lower severity and a low EPSS score (0.25%). Track it; it rarely justifies an emergency change on its own.
Description
Memory safety bugs present in Firefox 133, Thunderbird 133, Firefox ESR 128.5, and Thunderbird 128.5. 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 was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.
- CVSS 3.1
- 5.1 MEDIUMCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- EPSS
- 0.25% probability · 16th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1827142%2C1932783Broken Link, Issue Tracking
- https://www.mozilla.org/security/advisories/mfsa2025-01/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-02/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-04/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-05/Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2025/01/msg00004.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.