CVE-2025-0247
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?
EPSS puts the probability of exploitation in the next 30 days at 10.6%, higher than 96% of all known CVEs. Patch or mitigate before the next change window.
Description
Memory safety bugs present in Firefox 133 and Thunderbird 133. 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 and Thunderbird 134.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 10.61% probability · 96th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
EPSS moved from 10.6% on 14 October 2026 to 10.6% on 26 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
References
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1835193%2C1910021%2C1919803%2C1931576%2C1931948%2C1932173Broken Link, Issue Tracking
- https://www.mozilla.org/security/advisories/mfsa2025-01/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-04/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.