CVE-2026-8958

high

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.

References

https://www.mozilla.org/security/advisories/mfsa2026-51/

https://www.mozilla.org/security/advisories/mfsa2026-50/

https://www.mozilla.org/security/advisories/mfsa2026-48/

https://www.mozilla.org/security/advisories/mfsa2026-46/

https://bugzilla.mozilla.org/show_bug.cgi?id=2034713

Details

Source: Mitre, NVD

Published: 2026-05-19

Updated: 2026-05-20

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:N

Severity: High

CVSS v3

Base Score: 8.6

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N