CVE-2026-8950

critical · 9.3

Same-origin policy bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

9.3

CVSS

0.2%

EPSS (exploit prob.)

9th

EPSS percentile

2026-05-19

Published

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

Weaknesses

CWE-346

Affected products

Vendor	Product	Affected versions
mozilla	firefox	< 140.11.0
mozilla	firefox	< 151.0.0
mozilla	thunderbird	< 140.11
mozilla	thunderbird	< 151.0.0

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

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1965430
https://www.mozilla.org/security/advisories/mfsa2026-46/
https://www.mozilla.org/security/advisories/mfsa2026-48/
https://www.mozilla.org/security/advisories/mfsa2026-50/
https://www.mozilla.org/security/advisories/mfsa2026-51/

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-8950