CVE-2026-12304

critical · 9.1

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.

9.1

CVSS

0.2%

EPSS (exploit prob.)

9th

EPSS percentile

2026-06-16

Published

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Weaknesses

CWE-346

Affected products

Vendor	Product	Affected versions
mozilla	firefox	< 140.12.0
mozilla	firefox	< 152.0.0
mozilla	thunderbird	< 140.12.0
mozilla	thunderbird	< 152.0.0

Check a specific version with /api/v1/cve/match.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2034944
https://www.mozilla.org/security/advisories/mfsa2026-57/
https://www.mozilla.org/security/advisories/mfsa2026-58/
https://www.mozilla.org/security/advisories/mfsa2026-60/
https://www.mozilla.org/security/advisories/mfsa2026-61/

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-12304