CVE-2026-0881
Critical · CVSS 10.0Firefox / Thunderbird — Sandbox escape via Messaging System component (improper access control / protection mechanism failure)
- CVSS
- 10.0
- nvd
- EPSS
- —
- KEV
- No
- Class
- other
- CWE-284, CWE-693
Description
Sandbox escape in the Messaging System component. This vulnerability was fixed in Firefox 147 and Thunderbird 147.
Search profile — drives PoC discovery
Symbols Messaging Systemsandbox escapemfsa2026-01mfsa2026-04bug 2005845CWE-284CWE-693
Keywords CVE-2026-0881Firefox sandbox escapeThunderbird sandbox escapeMessaging System sandboxmfsa2026-01mfsa2026-04Firefox 147Thunderbird 147bugzilla 2005845CWE-284 FirefoxCWE-693 Firefoxprotection mechanism failure Firefox
Versions: Firefox < 147, Thunderbird < 147
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2005845
- https://www.mozilla.org/security/advisories/mfsa2026-01/
- https://www.mozilla.org/security/advisories/mfsa2026-04/
- https://access.redhat.com/security/cve/CVE-2026-0881
- https://bugzilla.redhat.com/show_bug.cgi?id=2428970
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0881.json
Status: enriched · ingested 2026-06-30T06:00:22.000Z · profiled 2026-06-30T18:30:14.000Z