VulnerabilityModified

CVE-2025-9187

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.

CRITICAL 9.8EPSS 0.45%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.45%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Memory safety bugs present in Firefox 141 and Thunderbird 141. 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 142 and Thunderbird 142.

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: 0.45% probability · 38th percentile
CISA KEV: Not listed
Weakness: CWE-119
Affected: mozilla/firefox · mozilla/thunderbird
Source: security@mozilla.org

References

https://bugzilla.mozilla.org/buglist.cgi?bug_id=1825621%2C1970079%2C1976736%2C1979072Broken Link
https://www.mozilla.org/security/advisories/mfsa2025-64/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-70/Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.