What is CVE-2026-12313?

CVE-2026-12313 is a medium-severity vulnerability in Mozilla Firefox, classified under Improper Privilege Management. CVSS score: 4.7/10. Published 2026-06-16.

How severe is CVE-2026-12313?

Medium severity. CVSS v3 base score is 4.7 out of 10.

Privilege escalation in Mozilla Firefox

CVE-2026-12313

Information disclosure, sandbox escape in the Security: Process Sandboxing component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.

Vulnerability class: Privilege Escalation

CVSS v3 metric

CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N.

Affected products

Mozilla Firefox — versions 140.12, 152
Mozilla Thunderbird — versions 140.12, 152

Weakness classification (CWE)

CWE-269 — Improper Privilege Management

References

security@mozilla.org
security@mozilla.org
security@mozilla.org
security@mozilla.org
security@mozilla.org

Frequently asked questions

What is CVE-2026-12313?: CVE-2026-12313 is a medium-severity vulnerability in Mozilla Firefox, classified under Improper Privilege Management. CVSS score: 4.7/10. Published 2026-06-16.
How severe is CVE-2026-12313?: Medium severity. CVSS v3 base score is 4.7 out of 10.