CVE-2026-2799highCWE-416

CVE-2026-2799: high-severity vulnerability in Mozilla Firefox

Use-after-free in the DOM: Core & HTML component

Published 24 Feb 2026 · Updated 15 Jul 2026

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21Vexday Risk Score

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

ssvc Trackcvss 8.8epss 0.5%

Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 148 and Thunderbird 148.

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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In the same product, most dangerous first.

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References

https://access.redhat.com/security/cve/CVE-2026-2799 https://bugzilla.mozilla.org/show_bug.cgi?id=2014551 https://bugzilla.redhat.com/show_bug.cgi?id=2442303 https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-2799.json https://www.mozilla.org/security/advisories/mfsa2026-13/https://www.mozilla.org/security/advisories/mfsa2026-16/