CVE-2026-4723

CWE-416 — Use After FreeCWE-8259 documents8 sources
Severity
9.8CRITICAL
EPSS
0.0%
top 94.65%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Mozilla FirefoxMozilla Thunderbird
Timeline
PublishedMar 24

Description

Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 149 and Thunderbird < 149.

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 Packages3 packages

▶CVEListV5mozilla/firefoxunspecified — 149
▶NVDmozilla/firefox< 149.0
▶CVEListV5mozilla/thunderbirdunspecified — 149

🔴Vulnerability Details

3
OSV
CVE-2026-4723: Use-after-free in the JavaScript Engine component↗2026-03-24
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CVEList
Use-after-free in the JavaScript Engine component↗2026-03-24
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GHSA
GHSA-c97j-hmj5-572h: Use-after-free in the JavaScript Engine component↗2026-03-24
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📋Vendor Advisories

4
Red Hat
firefox: Use-after-free in the JavaScript Engine component↗2026-03-24
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Debian
CVE-2026-4723: firefox - Use-after-free in the JavaScript Engine component. This vulnerability affects Fi...↗2026
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Mozilla
Mozilla Foundation Security Advisory 2026-23: CVE-2026-4723↗
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Mozilla
Mozilla Foundation Security Advisory 2026-20: CVE-2026-4723↗
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🕵️Threat Intelligence

1
Wiz
CVE-2026-4723 Impact, Exploitability, and Mitigation Steps | Wiz↗
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CVE-2026-4723 (CRITICAL CVSS 9.8) | Use-after-free in the JavaScript En | cvebase.io