CVE-2025-0240

low-risk

Published 2025-01-07

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.

Do I need to act?

0.05% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 4.0/10 Medium

LOCAL / LOW complexity

Affected Products (3)

Firefox

Thunderbird

Affected Vendors

Mozilla

References (6)

Issue Tracking https://bugzilla.mozilla.org/show_bug.cgi?id=1929623

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2025-01/

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2025-02/

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2025-04/

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2025-05/

https://lists.debian.org/debian-lts-announce/2025/01/msg00004.html

/ 100

low-risk

Severity 14/34 · Moderate

Exploitability 0/34 · Minimal

Exposure 9/34 · Low