Vulnerability in Mozilla Firefox
CVE-2025-1936
jar: URLs retrieve local file content packaged in a ZIP archive. The null and everything after it was ignored when retrieving the content from the archive, but the fake extension after the null was used to determine the type of content. This could have been used to hide code in a web extension disguised as something else like an image. This vulnerability was fixed in Firefox 136, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.004 (36.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000
Affected products
- Mozilla Firefox — versions 128.8, 136
- Mozilla Thunderbird — versions 128.8, 136
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required)
- www.mozilla.org/security/advisories/mfsa2025-14/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-16/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-17/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-18/ (Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2025-1936?
- CVE-2025-1936 is a high-severity vulnerability in Mozilla Firefox, classified under CWE-158. CVSS score: 7.3/10. Published 2025-03-04.
- How severe is CVE-2025-1936?
- High severity. CVSS v3 base score is 7.3 out of 10.
- Is CVE-2025-1936 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.