Stalled popup navigation could allow address bar origin spoofing in Firefox for iOS

published 2026-08-31 2 mo ago modified 2026-09-03 2 mo ago also EUVD-2026-68739

cvss: 5.4; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits: 0; none known

A malicious webpage could stall a popup's cross-origin navigation after commit, causing the address bar to display the destination origin while continuing to render attacker-controlled content. This vulnerability was fixed in Firefox for iOS 155.0.

Patch / fix

fixed in 1

mozilla firefox 155.0

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-08-31)

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
CNA	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L

Affected products

Mozilla Firefox for iOS

Classification

Weakness

CWE-451 User Interface (UI) Misrepresentation of Critical Information

References

mozilla.org /security/advisories/mfsa2026-81/
vendor-advisory
bugzilla.mozilla.org /show_bug.cgi?id=2052758
permissions-required

Sources

CVE List CVE-2026-81267
NVD CVE-2026-81267

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