CVE-2026-4702 - Vulnerability Analysis

Overview

Firefox < 149 and Firefox ESR < 140.9 contain a code execution vulnerability caused by JIT miscompilation in the JavaScript Engine, letting attackers execute arbitrary code, exploit requires crafted JavaScript code execution.

Severity & Score

Impact

Attackers can execute arbitrary code remotely via crafted JavaScript, potentially compromising the user's system.

Mitigation

Update to Firefox 149 or later and Firefox ESR 140.9 or later.

References

• https://www.mozilla.org/security/advisories/mfsa2026-24/
• https://bugzilla.mozilla.org/show_bug.cgi?id=2013560
• https://www.mozilla.org/security/advisories/mfsa2026-20/
• https://www.mozilla.org/security/advisories/mfsa2026-22/
• https://www.mozilla.org/security/advisories/mfsa2026-23/

Related Resources

• Vulnerability Intelligence Dashboard
• Credential Scanner