CVE-2026-8958 Security Details

CVE ID

CVE-2026-8958

CWE

CWE-668

CWE-693

CVE 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.

Published

May 21, 2026

CVSS Score & Severity

8.6High

CVSS Vector

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

EPSS Score

0.058%

Malware

malware

KEV Status

Not in KEV Catalog: No known exploits

Affected Ecosystems

affected

Source

National Vulnerability Database

References

mozilla.orgPROJECT