Networking Vulnerability in Mozilla Firefox and Firefox ESR Products
CVE-2026-6776

7.8HIGH

Key Information:

Vendor

Mozilla
Status
Firefox
Vendor
CVE Published:
21 April 2026

What is CVE-2026-6776?

This vulnerability arises from incorrect boundary conditions in the WebRTC component of Mozilla Firefox, which can lead to unintended consequences during network operations. It has been addressed in the latest releases of Firefox and Firefox ESR, ensuring users are protected from potential exploits that could leverage this defect.

Affected Version(s)

Firefox 140.10

Firefox 150

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2021770
https://www.mozilla.org/security/advisories/mfsa2026-30/
https://www.mozilla.org/security/advisories/mfsa2026-32/

CVSS V3.1

Score:
7.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Nan Wang
.