CVE-2024-9391

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-10-01 · updated 2026-06-17
Weakness: CWE-290

Description

A user who enables full-screen mode on a specially crafted web page could potentially be prevented from exiting full screen mode. This may allow spoofing of other sites as the address bar is no longer visible. *This bug only affects Firefox Focus for Android. Other versions of Firefox are unaffected.* This vulnerability affects Firefox < 131.

Affected products

Mozilla Firefox: before 131.0 — fixed in 131.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 131.0. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1892407
https://www.mozilla.org/security/advisories/mfsa2024-46/

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