CVE-2026-6776

Incorrect boundary conditions in the WebRTC: Networking component

CVSS 7.8 HIGHEPSS 0.1%CWE-119

Vexday Risk Score

21Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 7.8EPSS 0.1%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

21 Apr 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

Incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

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

Affected products

Mozilla · Firefox Mozilla · Thunderbird

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/https://www.mozilla.org/security/advisories/mfsa2026-33/https://www.mozilla.org/security/advisories/mfsa2026-34/