What is CVE-2026-81267?

CVE-2026-81267 is a medium-severity vulnerability in Mozilla Firefox Mobile, classified under User Interface (UI) Misrepresentation of Critical Information. CVSS score: 5.4/10. Published 2026-08-31.

How severe is CVE-2026-81267?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Vulnerability in Mozilla Firefox Mobile

CVE-2026-81267

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.

Published 2026-08-31 · last modified 2026-09-03.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L.

EPSS exploit prediction

EPSS: 0.003 (16.2th percentile), scored 2026-10-16.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 16.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Mozilla Firefox Mobile

Weakness classification (CWE)

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

References

bugzilla.mozilla.org/show_bug.cgi (Permissions Required)
www.mozilla.org/security/advisories/mfsa2026-81/ (Vendor Advisory)

Frequently asked questions

What is CVE-2026-81267?: CVE-2026-81267 is a medium-severity vulnerability in Mozilla Firefox Mobile, classified under User Interface (UI) Misrepresentation of Critical Information. CVSS score: 5.4/10. Published 2026-08-31.
How severe is CVE-2026-81267?: Medium severity. CVSS v3 base score is 5.4 out of 10.