What is CVE-2026-103417?

CVE-2026-103417 is a medium-severity vulnerability, classified under Origin Validation Error. CVSS score: 5.5/10. Published 2026-10-13.

How severe is CVE-2026-103417?

Medium severity. CVSS v3 base score is 5.5 out of 10.

CVE-2026-103417

CVE-2026-103417

Firefox for iOS could autofill saved credentials into a new page if cross-origin navigation occurred while the saved-login UI was open. Autofill was not bound to the originating page or rejected when its origin changed. This vulnerability was fixed in Firefox for iOS 157.1.

Published 2026-10-13 · last modified 2026-10-13.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Weakness classification (CWE)

CWE-346 — Origin Validation Error

References

bugzilla.mozilla.org/show_bug.cgi
www.mozilla.org/security/advisories/mfsa2026-105/

Frequently asked questions

What is CVE-2026-103417?: CVE-2026-103417 is a medium-severity vulnerability, classified under Origin Validation Error. CVSS score: 5.5/10. Published 2026-10-13.
How severe is CVE-2026-103417?: Medium severity. CVSS v3 base score is 5.5 out of 10.