CVE-2026-4689

Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component

CVSS 10 CRITICALEPSS 0.7%CWE-120 CWE-190

Vexday Risk Score

28Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 10EPSS 0.7%KEV nãoPoC —Nuclei —Metasploit —Patch referenciado

Lifecycle

24 Mar 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected products

Mozilla · Firefox Mozilla · Thunderbird

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References