CVE-2025-0240

MEDIUM 4.0

Compartment mismatch when parsing JavaScript JSON module

CVSS Score

4.0

EPSS Score

0.0%

EPSS Percentile

0th

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.

Vendor	mozilla
Product	firefox
Ecosystems	Browser JavaScript
Industries	Technology
Published	Jan 7, 2025
Last Updated	Apr 13, 2026

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Affected Versions

Mozilla / Firefox

All versions affected

Mozilla / Thunderbird

All versions affected

References

NVD ↗ CVE.org ↗ EPSS Data ↗

bugzilla.mozilla.org: https://bugzilla.mozilla.org/show_bug.cgi?id=1929623 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-01/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-02/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-04/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-05/ lists.debian.org: https://lists.debian.org/debian-lts-announce/2025/01/msg00004.html

Credits

Nils Bars