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. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.

CVSS 3.1

4.0CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS

0.7% chance of exploitation in the next 30 days; higher than 51% of CVEs (scores of 2026-10-25)

CWE

CWE-416

Published

2025-01-07

Modified

2026-10-05

Record from

the NVD, synced 2026-10-19

Affected

• mozilla:firefox
• mozilla:thunderbird

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1929623
• https://www.mozilla.org/security/advisories/mfsa2025-01/
• https://www.mozilla.org/security/advisories/mfsa2025-02/
• https://www.mozilla.org/security/advisories/mfsa2025-04/
• https://www.mozilla.org/security/advisories/mfsa2025-05/

Check your stackJSON