CVE-2026-7321

Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component

CVSS 9.6 CRITICALEPSS 0.3%CWE-120

Vexday Risk Score

28Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 9.6EPSS 0.3%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

28 Apr 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Thunderbird 150, Firefox ESR 140.10.1, and Thunderbird 140.10.1.

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

Affected products

Mozilla · Firefox Mozilla · Thunderbird

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2029461 https://www.mozilla.org/security/advisories/mfsa2026-30/https://www.mozilla.org/security/advisories/mfsa2026-33/https://www.mozilla.org/security/advisories/mfsa2026-36/https://www.mozilla.org/security/advisories/mfsa2026-39/