CVE-2026-2804 — Use After Free in Mozilla Firefox

CWE-416 — Use After Free9 documents8 sources
Severity
5.4MEDIUMNVD
EPSS
0.0%
top 90.18%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Mozilla FirefoxMozilla Thunderbird
Timeline
PublishedFeb 24

Description

Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 148 and Thunderbird 148.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:NExploitability: 2.8 | Impact: 2.5

Affected Packages2 packages

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

🔴Vulnerability Details

3
OSV
CVE-2026-2804: Use-after-free in the JavaScript: WebAssembly component↗2026-02-24
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GHSA
GHSA-3922-j2hh-9qcf: Use-after-free in the JavaScript: WebAssembly component↗2026-02-24
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CVEList
Use-after-free in the JavaScript: WebAssembly component↗2026-02-24
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📋Vendor Advisories

4
Red Hat
firefox: thunderbird: Use-after-free in the JavaScript: WebAssembly component↗2026-02-24
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Debian
CVE-2026-2804: firefox - Use-after-free in the JavaScript: WebAssembly component. This vulnerability affe...↗2026
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Mozilla
Mozilla Foundation Security Advisory 2026-13: CVE-2026-2804↗
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Mozilla
Mozilla Foundation Security Advisory 2026-16: CVE-2026-2804↗
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🕵️Threat Intelligence

1
Wiz
CVE-2026-2804 Impact, Exploitability, and Mitigation Steps | Wiz↗
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CVE-2026-2804 — Use After Free in Mozilla Firefox | cvebase