CVE-2026-4700 - Vulnerability Analysis

Overview

Firefox < 149 and Firefox ESR < 140.9 contain a mitigation bypass vulnerability in the Networking: HTTP component, letting attackers bypass security mitigations, exploit requires no special conditions.

Severity & Score

Impact

Attackers can bypass security mitigations, potentially leading to further exploitation or compromise.

Mitigation

Update to Firefox 149, Firefox ESR 140.9 or later versions.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2003766
• https://www.mozilla.org/security/advisories/mfsa2026-20/
• https://www.mozilla.org/security/advisories/mfsa2026-22/
• https://www.mozilla.org/security/advisories/mfsa2026-23/
• https://www.mozilla.org/security/advisories/mfsa2026-24/

Related Resources

• Vulnerability Intelligence Dashboard
• Credential Scanner