CVE-2026-16406

CRITICAL

Published Jul 21, 2026 Modified Jul 21, 2026 CWE-693

Description

Mitigation bypass in the Networking component. This vulnerability was fixed in Firefox 153.

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CVSS v3.1 Score

9.1

CRITICAL

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

Weakness Type (CWE)

CWE-693 CWE-693

References

Other References

https://bugzilla.mozilla.org/show_bug.cgi?id=2040382 https://www.mozilla.org/security/advisories/mfsa2026-68/

Frequently Asked Questions

What is CVE-2026-16406? +

Mitigation bypass in the Networking component. This vulnerability was fixed in Firefox 153. It has a CVSS v3.1 base score of 9.1 (CRITICAL).

How severe is CVE-2026-16406? +

CVE-2026-16406 has a CVSS v3.1 score of 9.1 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately.

How do I check if I'm vulnerable to CVE-2026-16406? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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