CVE-2025-3029

HIGH 7.3

URL Bar Spoofing via non-BMP Unicode characters

CVSS Score

7.3

EPSS Score

0.0%

EPSS Percentile

0th

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.

Vendor	mozilla
Product	firefox
Ecosystems	Browser JavaScript
Industries	Technology
Published	Apr 1, 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=1952213 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-20/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-22/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-23/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-24/ lists.debian.org: https://lists.debian.org/debian-lts-announce/2025/04/msg00005.html

Credits

Renwa Hiwa