VulnerabilityModified
CVE-2026-0881
This vulnerability was fixed in Firefox 147 and Thunderbird 147.
CRITICAL 10.0EPSS 0.36%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.36%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Sandbox escape in the Messaging System component. This vulnerability was fixed in Firefox 147 and Thunderbird 147.
- CVSS 3.1
- 10.0 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 0.36% probability · 29th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-284, CWE-693
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2005845Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-01/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-04/Vendor Advisory
- 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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.