CVE-2026-2771 - Vulnerability Analysis
CriticalCVSS: 9.8Last Updated: February 25, 2026
Mozilla Firefox - Undefined Behavior
Published: February 24, 2026Updated: February 25, 2026Remote Exploitable
Overview
Mozilla Firefox < 148, Firefox ESR < 115.33, and Firefox ESR < 140.8 contain an undefined behavior vulnerability in the DOM Core & HTML component, letting attackers potentially cause unexpected behavior, exploit requires crafted web content.
Severity & Score
Severity: Critical
CVSS Score: 9.8
Impact
Attackers can cause unexpected behavior in the browser, potentially leading to security issues or crashes.
Mitigation
Update to Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8 or later.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2014593
- https://www.mozilla.org/security/advisories/mfsa2026-13/
- https://www.mozilla.org/security/advisories/mfsa2026-14/
- https://www.mozilla.org/security/advisories/mfsa2026-15/
- https://www.mozilla.org/security/advisories/mfsa2026-16/
- https://www.mozilla.org/security/advisories/mfsa2026-17/
Related Resources
Details
- CVE ID
- CVE-2026-2771
- Severity
- Critical
- CVSS Score
- 9.8
- Type
- undefined
- Status
- confirmed
CWE
- NVD-CWE-noinfo
CVSS Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H