CVE-2026-7321

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

Published Apr 28, 2026 CVSS 3.1 · 9.6 Critical EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4555-1 firefox-esr security update
Debian DLA Debian DLA DLA-4562-1 thunderbird security update
Debian DSA Debian DSA DSA-6236-1 firefox-esr security update
Debian DSA Debian DSA DSA-6242-1 thunderbird security update
History
Type Values Removed Values Added
First Time appeared Mozilla thunderbird
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
Vendors & Products Mozilla thunderbird
Type Values Removed Values Added
Description Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Thunderbird 150, and Firefox ESR 140.10.1. 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.
References
Type Values Removed Values Added
Description Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox ESR 140.10.1. Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Thunderbird 150, and Firefox ESR 140.10.1.
References
Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Vendors & Products Mozilla
Mozilla firefox
Type Values Removed Values Added
Weaknesses CWE-120
Metrics cvssV3_1

{'score': 9.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox ESR 140.10.1.
Title Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mozilla
Published
Updated
Apr 30, 2026, 5:19 PM
Reserved
Apr 28, 2026, 1:42 PM
Status
Analyzed
Published
Apr 28, 2026, 3:16 PM
Modified
Oct 26, 2026, 8:10 PM
Severity
Moderate
Public date
Apr 28, 2026, 1:49 PM