What is CVE-2026-16412?

CVE-2026-16412 is a critical-severity vulnerability in Mozilla Firefox, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.8/10. Published 2026-07-21.

How severe is CVE-2026-16412?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Mozilla Firefox

CVE-2026-16412

Memory safety bugs present in Firefox ESR 140.12 and Firefox 152. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerabil…

Vulnerability class: Buffer Overflow

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Mozilla Firefox — versions 140.13, 153

Weakness classification (CWE)

CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer

References

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

Frequently asked questions

What is CVE-2026-16412?: CVE-2026-16412 is a critical-severity vulnerability in Mozilla Firefox, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.8/10. Published 2026-07-21.
How severe is CVE-2026-16412?: Critical severity. CVSS v3 base score is 9.8 out of 10.