Vulnerability in Mozilla Firefox
CVE-2026-2802
Race condition in the JavaScript: GC component. This vulnerability was fixed in Firefox 148 and Thunderbird 148.
Vulnerability class: Race Condition
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (9.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 9.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001
Affected products
- Mozilla Firefox — versions 148
- Mozilla Thunderbird — versions 148
Weakness classification (CWE)
References
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required)
- www.mozilla.org/security/advisories/mfsa2026-13/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-16/ (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-2802?
- CVE-2026-2802 is a medium-severity vulnerability in Mozilla Firefox, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 4.2/10. Published 2026-02-24.
- How severe is CVE-2026-2802?
- Medium severity. CVSS v3 base score is 4.2 out of 10.