CVE-2026-12304
9.1
CRITICAL
CVSS 3.1
Description
Same-origin policy bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.
How to fix CVE-2026-12304
No fixed version has been published yet. Mitigate by removing the affected package or applying upstream guidance from the references below.
- Debian/firefox-esr—no fix listed
- Debian/thunderbird—no fix listed
Is CVE-2026-12304 being exploited?
No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-12304.
Affected packages (2)
- from 0
- from 0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |