Buffer overflow in Mozilla Firefox
CVE-2026-5733
Incorrect boundary conditions in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 149.0.2 and Thunderbird 149.0.2.
Vulnerability class: Buffer Overflow
EPSS: 0.003 (22.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
Affected products
- Mozilla Firefox — versions 149.0.2
- Mozilla Thunderbird — versions 149.0.2
Weakness classification (CWE)
References
- security@mozilla.org (Permissions Required, Issue Tracking)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-5733?
- CVE-2026-5733 is a high-severity vulnerability in Mozilla Firefox, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.8/10. Published 2026-04-07.
- How severe is CVE-2026-5733?
- High severity. CVSS v3 base score is 8.8 out of 10.