Vulnerability in Mozilla Firefox
CVE-2025-3029
A crafted URL containing specific Unicode characters could have hidden the true origin of the page, resulting in a potential spoofing attack. This vulnerability was fixed in Firefox 137, Firefox ESR 128.9, Thunderbird 137, and Thunderbird 128.9.
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: 0.003 (25.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 25.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Mozilla Firefox — versions 128.9, 137
- Mozilla Thunderbird — versions 128.9, 137
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required, Issue Tracking)
- www.mozilla.org/security/advisories/mfsa2025-20/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-22/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-23/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-24/ (Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2025-3029?
- CVE-2025-3029 is a high-severity vulnerability in Mozilla Firefox, classified under Authentication Bypass by Spoofing. CVSS score: 7.3/10. Published 2025-04-01.
- How severe is CVE-2025-3029?
- High severity. CVSS v3 base score is 7.3 out of 10.
- Is CVE-2025-3029 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.