CVE-2026-7321
published 2026-04-28CVE-2026-7321: Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Thunderbird 150, Firefox…
PriorityP347critical9.6CVSS 3.1
AVNACLPRNUIRSCCHIHAH
EPSS
0.26%
17.3th percentile
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.
Affected
10 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < 140.10.1 | 140.10.1 |
| mozilla | firefox | < 150.0 | 150.0 |
| mozilla | firefox | — | — |
| mozilla | firefox_esr | < Firefox ESR 140.10.1 | Firefox ESR 140.10.1 |
| mozilla | thunderbird | < Thunderbird 140.10.1 | Thunderbird 140.10.1 |
| mozilla | thunderbird | < 140.10.1 | 140.10.1 |
| mozilla | thunderbird | < 150.0 | 150.0 |
| mozilla | thunderbird | — | — |
| rhel10 | firefox-flatpak | — | — |
| rhel10 | thunderbird-flatpak | — | — |
CVSS provenance
nvdv3.19.6CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
vendor_redhat9.6CRITICAL
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Red Hat
firefox: thunderbird: webrtc: Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component
vendor_redhat·2026-04-28·CVSS 9.6
CVE-2026-7321 [CRITICAL] CWE-501 firefox: thunderbird: webrtc: Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component
firefox: thunderbird: webrtc: Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Package: firefox (Red Hat Enterprise Linux 10) - Affected
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: thunderbird (Red Hat Enterprise Linux 10) - Affected
Package: firefox (Red Hat Enterprise Linux 6) - Out of support scope
P
Mozilla
Mozilla Foundation Security Advisory 2026-39: CVE-2026-7321
vendor_mozilla·CVSS 9.6
CVE-2026-7321 [CRITICAL] Mozilla Foundation Security Advisory 2026-39: CVE-2026-7321
Mozilla Foundation Security Advisory 2026-39
CVE: CVE-2026-7321
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.10.1
Mozilla
Mozilla Foundation Security Advisory 2026-36: CVE-2026-7321
vendor_mozilla
CVE-2026-7321 Mozilla Foundation Security Advisory 2026-36: CVE-2026-7321
Mozilla Foundation Security Advisory 2026-36
CVE: CVE-2026-7321
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.10.1
GHSA
GHSA-jjvw-q2ff-g9g3: Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component
ghsa_unreviewed·2026-04-28
CVE-2026-7321 [CRITICAL] CWE-120 GHSA-jjvw-q2ff-g9g3: Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component
Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox ESR 140.10.1.
VulDB
Mozilla Firefox ESR up to 140.10.0 WebRTC sandbox (EUVD-2026-26058)
vuldb·2026-04-28·CVSS 9.6
CVE-2026-7321 [CRITICAL] Mozilla Firefox ESR up to 140.10.0 WebRTC sandbox (EUVD-2026-26058)
A vulnerability marked as critical has been reported in Mozilla Firefox ESR up to 140.10.0. The impacted element is an unknown function of the component WebRTC. The manipulation leads to sandbox issue.
This vulnerability is listed as CVE-2026-7321. The attack may be initiated remotely. There is no available exploit.
It is suggested to upgrade the affected component.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-7321 qt5-qtwebengine: WebRTC: Sandbox Escape due to Incorrect Boundary Conditions [epel-all]
bugzilla·2026-05-01·CVSS 9.6
CVE-2026-7321 [CRITICAL] CVE-2026-7321 qt5-qtwebengine: WebRTC: Sandbox Escape due to Incorrect Boundary Conditions [epel-all]
CVE-2026-7321 qt5-qtwebengine: WebRTC: Sandbox Escape due to Incorrect Boundary Conditions [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-7321 qt5-qtwebengine: WebRTC: Sandbox Escape due to Incorrect Boundary Conditions [fedora-all]
bugzilla·2026-05-01·CVSS 9.6
CVE-2026-7321 [CRITICAL] CVE-2026-7321 qt5-qtwebengine: WebRTC: Sandbox Escape due to Incorrect Boundary Conditions [fedora-all]
CVE-2026-7321 qt5-qtwebengine: WebRTC: Sandbox Escape due to Incorrect Boundary Conditions [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-7321 qt6-qtwebengine: WebRTC: Sandbox Escape due to Incorrect Boundary Conditions [epel-all]
bugzilla·2026-05-01·CVSS 9.6
CVE-2026-7321 [CRITICAL] CVE-2026-7321 qt6-qtwebengine: WebRTC: Sandbox Escape due to Incorrect Boundary Conditions [epel-all]
CVE-2026-7321 qt6-qtwebengine: WebRTC: Sandbox Escape due to Incorrect Boundary Conditions [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-7321 pjproject: WebRTC: Sandbox Escape due to Incorrect Boundary Conditions [fedora-all]
bugzilla·2026-05-01·CVSS 9.6
CVE-2026-7321 [CRITICAL] CVE-2026-7321 pjproject: WebRTC: Sandbox Escape due to Incorrect Boundary Conditions [fedora-all]
CVE-2026-7321 pjproject: WebRTC: Sandbox Escape due to Incorrect Boundary Conditions [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-7321 firefox: thunderbird: webrtc: Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component
bugzilla·2026-04-28·CVSS 9.6
CVE-2026-7321 [CRITICAL] CVE-2026-7321 firefox: thunderbird: webrtc: Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component
CVE-2026-7321 firefox: thunderbird: webrtc: Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component
Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox ESR 140.10.1.
2026-04-28
Published