VulnerabilityModified
CVE-2026-2779
This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
CRITICAL 9.8EPSS 0.60%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.60%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Incorrect boundary conditions in the Networking: JAR component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
- 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
- 0.60% probability · 47th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-119
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1164141Issue Tracking, Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-13/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-15/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-16/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-17/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.