Description
The Firefox and Firefox Focus UI for the Android custom tab feature only showed the "site" that was loaded, not the full hostname. User supplied content hosted on a subdomain of a site could have been used to fool a user into thinking it was content from a different subdomain of that site. This vulnerability was fixed in Firefox 144.
Affected products
mozilla: firefox; google: android
References3
- www.mozilla.org/security/advisories/mfsa2025-81/ Vendor Advisory
- bugzilla.mozilla.org/show_bug.cgi?id=1979534 Issue TrackingPermissions Required
- bugzilla.mozilla.org/show_bug.cgi?id=1984370 Issue TrackingPermissions Required
Metrics
- CVSS 3.1
-
8.1
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - EPSS — exploit probability
- 0% percentile: 19 · as of 9 November 2026
- CWE
- CWE-451
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