CVE-2025-0240: Parsing a JavaScript module as JSON could, under some circumstances, cause cross-compartment access
Source GCVE Database
Not known to be exploited · CVSS 4.0 Medium.
Data as of 30 Oct 2026, 15:49 UTC
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 7 Jan 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
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 affects Firefox < 134 and Firefox ESR < 128.6.
References
- nvd.nist.gov/vuln/detail/CVE-2025-0240 (opens in a new tab)
- bugzilla.mozilla.org/show_bug.cgi?id=1929623 (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/01/msg00004.html (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-01 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-02 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-04 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-05 (opens in a new tab)