Use After Free in Mozilla Firefox
CVE-2026-8090
Use-after-free in the DOM: Networking component. This vulnerability was fixed in Firefox 150.0.2, Firefox ESR 140.10.2, Firefox ESR 115.35.2, Thunderbird 150.0.2, and Thunderbird 140.10.2.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.004 (37.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Mozilla Firefox — versions 115.35.2, 140.10.2, 150.0.2
- Mozilla Thunderbird — versions 140.10.2, 150.0.2
Weakness classification (CWE)
References
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required)
- www.mozilla.org/security/advisories/mfsa2026-40/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-41/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-42/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-43/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-44/ (Vendor Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-8090?
- CVE-2026-8090 is a high-severity vulnerability in Mozilla Firefox, classified under Use After Free. CVSS score: 7.3/10. Published 2026-05-07.
- How severe is CVE-2026-8090?
- High severity. CVSS v3 base score is 7.3 out of 10.