CVE-2026-117921

HighCVSS 8.8/10Last modified Nov 4, 2026

Description

Use-after-free in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.

Metrics

CVSS 3.1 8.8/10CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-416

Affected software

VendorProductVersions
MozillaFirefox—
MozillaThunderbird—

References

Timeline

Published
Oct 27, 2026
Last modified
Nov 4, 2026
NVD status
Deferred

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CVE-2026-117921: High severity, CVSS 8.8 | Vulnix