CVE-2026-2776

Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software

CVSS 10 CRITICALEPSS 0.5%CWE-119

Vexday Risk Score

28Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 10EPSS 0.5%KEV nãoPoC —Nuclei —Metasploit —Patch referenciado

Lifecycle

24 Feb 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

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