Address bar spoofing on iOS using long hostnames

published 2025-01-11 21 mo ago modified 2026-10-05 35 d ago also EUVD-2025-3123

cvss: 6.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits: 0; none known

Long hostnames in URLs could be leveraged to obscure the actual host of the website or spoof the website address. This vulnerability was fixed in Firefox for iOS 134.

Patch / fix

fixed in 1

mozilla firefox 134

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 21 mo ago (2025-01-13)

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
CNA	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Affected products

Mozilla Firefox for iOS

Classification

Weakness

CWE-346 Origin Validation Error

References

mozilla.org /security/advisories/mfsa2025-06/
vendor-advisory
bugzilla.mozilla.org /show_bug.cgi?id=1419275
issue-tracking, permissions-required

Sources

CVE List CVE-2025-23109
NVD CVE-2025-23109

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary