CVE-2026-100818

CriticalCVSS 9.6/10Last modified Oct 5, 2026

Description

Sandbox escape due to use-after-free in the Widget: Gtk component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, and Firefox ESR 140.17.

Metrics

CVSS 3.1 9.6/10CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Weakness enumeration

CWE-416

Affected software

No affected versions have been published.

Timeline

Published
Sep 29, 2026
Last modified
Oct 5, 2026
NVD status
Analyzed

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CVE-2026-100818: Critical severity, CVSS 9.6 | Vulnix