CVE-2025-0240 — Use After Free in Mozilla Firefox

CWE-416 — Use After Free13 documents8 sources
Severity
4.0MEDIUMNVD
OSV5.4
EPSS
0.0%
top 85.29%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Mozilla ThunderbirdMozilla Firefox
Timeline
PublishedJan 7
Latest updateFeb 2

Description

Parsing a JavaScript module as JSON could, under some circumstances, cause cross-compartment access, which may result in a use-after-free. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NExploitability: 2.5 | Impact: 1.4

Affected Packages4 packages

▶NVDmozilla/thunderbird129.0 — 134.0+1
▶Debianmozilla/thunderbird< 1:128.6.0esr-1~deb11u1+3
▶NVDmozilla/firefox< 128.6.0+1
▶Ubuntumozilla/firefox< 134.0+build1-0ubuntu0.20.04.1

🔴Vulnerability Details

4
OSV
firefox vulnerabilities↗2025-01-09
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GHSA
GHSA-f3xq-g93v-w8cv: Parsing a JavaScript module as JSON could, under some circumstances, cause cross-compartment access, which may result in a use-after-free↗2025-01-07
▶
CVEList
Compartment mismatch when parsing JavaScript JSON module↗2025-01-07
▶
OSV
CVE-2025-0240: Parsing a JavaScript module as JSON could, under some circumstances, cause cross-compartment access, which may result in a use-after-free↗2025-01-07
▶

📋Vendor Advisories

8
Ubuntu
Thunderbird vulnerabilities↗2026-02-02
▶
Ubuntu
Firefox vulnerabilities↗2025-01-09
▶
Red Hat
firefox: Compartment mismatch when parsing JavaScript JSON module↗2025-01-07
▶
Debian
CVE-2025-0240: firefox - Parsing a JavaScript module as JSON could, under some circumstances, cause cross...↗2025
▶
Mozilla
Mozilla Foundation Security Advisory 2025-04: CVE-2025-0240↗
▶
CVE-2025-0240 — Use After Free in Mozilla Firefox | cvebase