CVE-2026-2778 - Vulnerability Analysis
CriticalCVSS: 10.0Last Updated: February 25, 2026
Firefox - Sandbox Escape
Published: February 24, 2026Updated: February 25, 2026Remote Exploitable
Overview
Firefox < 148, Firefox ESR < 115.33, and Firefox ESR < 140.8 contain a sandbox escape caused by incorrect boundary conditions in the DOM: Core & HTML component, letting attackers escape sandbox restrictions, exploit requires crafted web content.
Severity & Score
Severity: Critical
CVSS Score: 10.0
Impact
Attackers can escape sandbox restrictions, potentially executing arbitrary code or accessing sensitive data.
Mitigation
Update to Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8 or later.
References
- 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/
- https://bugzilla.mozilla.org/show_bug.cgi?id=2016358
- https://www.mozilla.org/security/advisories/mfsa2026-13/
Related Resources
Details
- CVE ID
- CVE-2026-2778
- Severity
- Critical
- CVSS Score
- 10.0
- Type
- sandbox_escape
- Status
- confirmed
CWE
- NVD-CWE-noinfo
CVSS Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H