CVE-2026-16375

critical · 9.8

Site isolation issue in the Networking: HTTP component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

9.8

CVSS

0.2%

EPSS (exploit prob.)

11th

EPSS percentile

2026-07-21

Published

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

Weaknesses

CWE-346

Affected products

Vendor	Product	Affected versions
mozilla	firefox	< 140.13.0
mozilla	firefox	< 153.0.0
mozilla	thunderbird	< 140.13.0
mozilla	thunderbird	>= 141.0, < 153.0

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

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2032140
https://www.mozilla.org/security/advisories/mfsa2026-68/
https://www.mozilla.org/security/advisories/mfsa2026-70/
https://www.mozilla.org/security/advisories/mfsa2026-71/
https://www.mozilla.org/security/advisories/mfsa2026-72/

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-16375