CVE-2026-2799 — Use After Free in Mozilla Firefox

CWE-416 — Use After Free9 documents8 sources
Severity
9.8CRITICALNVD
EPSS
0.0%
top 85.98%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Mozilla FirefoxMozilla Thunderbird
Timeline
PublishedFeb 24

Description

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

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitability: 3.9 | Impact: 5.9

Affected Packages2 packages

▶NVDmozilla/firefox< 148.0
▶NVDmozilla/thunderbird< 148.0

🔴Vulnerability Details

3
CVEList
Use-after-free in the DOM: Core & HTML component↗2026-02-24
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GHSA
GHSA-gvhp-5j8m-528x: Use-after-free in the DOM: Core & HTML component↗2026-02-24
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OSV
CVE-2026-2799: Use-after-free in the DOM: Core & HTML component↗2026-02-24
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📋Vendor Advisories

4
Red Hat
firefox: thunderbird: Use-after-free in the DOM: Core & HTML component↗2026-02-24
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Debian
CVE-2026-2799: firefox - Use-after-free in the DOM: Core & HTML component. This vulnerability affects Fir...↗2026
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Mozilla
Mozilla Foundation Security Advisory 2026-16: CVE-2026-2799↗
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Mozilla
Mozilla Foundation Security Advisory 2026-13: CVE-2026-2799↗
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🕵️Threat Intelligence

1
Wiz
CVE-2026-2799 Impact, Exploitability, and Mitigation Steps | Wiz↗
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CVE-2026-2799 — Use After Free in Mozilla Firefox | cvebase