CVE-2026-117956highCWE-824

CVE-2026-117956: high-severity vulnerability in Mozilla Firefox

Invalid pointer in the Nimbus Desktop Client component

Published 27 Oct 2026 · Updated 05 Nov 2026

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21Vexday Risk Score

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

ssvc Trackcvss 8.8epss 0.4%

Invalid pointer in the Nimbus Desktop Client component. This vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.

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

Affected products

Mozilla · Firefox Mozilla · Thunderbird

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References

https://bugzilla.mozilla.org/show_bug.cgi?id=2058659 https://www.mozilla.org/security/advisories/mfsa2026-118/https://www.mozilla.org/security/advisories/mfsa2026-120/https://www.mozilla.org/security/advisories/mfsa2026-121/https://www.mozilla.org/security/advisories/mfsa2026-122/