CVE-2026-4691criticalCWE-416CWE-825

CVE-2026-4691: critical vulnerability in Mozilla Firefox

Use-after-free in the CSS Parsing and Computation component

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28Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 9.8epss 0.5%
Use-after-free in the CSS Parsing and Computation 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:U/C:H/I:H/A:H
Affected products
Mozilla · FirefoxMozilla · Thunderbird
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