VulnerabilityAnalyzed
CVE-2026-8958
Information disclosure, sandbox escape in the Security: Process Sandboxing component.
HIGH 8.6EPSS 0.34%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.34%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Information disclosure, sandbox escape in the Security: Process Sandboxing component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
- CVSS 3.1
- 8.6 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- EPSS
- 0.34% probability · 28th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-668, CWE-693
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2034713Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-46/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-48/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-50/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-51/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.