CVE-2026-2776

10.0 CRITICAL

Published: February 24, 2026 Modified: February 28, 2026

Description

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

AI Explanation

Get an AI-powered plain-language explanation of this vulnerability and remediation steps.

CVSS v3.x Details

0.0 Low Medium High Critical 10.0

Vector String

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

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory

https://bugzilla.mozilla.org/show_bug.cgi?id=2015266

Source: security@mozilla.org

Issue Tracking Permissions Required

https://www.mozilla.org/security/advisories/mfsa2026-13/

Source: security@mozilla.org

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2026-14/

Source: security@mozilla.org

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2026-15/

Source: security@mozilla.org

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2026-16/

Source: security@mozilla.org

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2026-17/

Source: security@mozilla.org

Vendor Advisory

6 reference(s) from NVD

Quick Stats

CVSS v3 Score

10.0 / 10.0

EPSS (Exploit Probability)

0.1%

21th percentile

Exploitation Status

Not in CISA KEV

Weaknesses (CWE)

CWE-119

Affected Vendors

mozilla

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