Mozilla Firefox and Thunderbird Fullscreen Notification Spoofing Vulnerability

Vulnerability

A vulnerability exists in Firefox versions prior to 135 and Thunderbird versions prior to 135, where the fullscreen notification is unintentionally dismissed when fullscreen is quickly re-requested by the user. This behavior could be exploited to perform a spoofing attack.

Impact

Exploitation of this vulnerability could lead to a spoofing attack, where a user could be misled by the application's interface.

Remediation

Users can upgrade to Firefox 135 or Thunderbird 135 to address this vulnerability.

Added: Jun 9, 2025, 7:46 PM
Updated: Jun 9, 2025, 7:46 PM

Vulnerability Rating

Custom Algorithm
spread
8.4
impact
0.6
exploitability
4.2
remediation
7.7
relevance
0.0
threat
0.0
urgency
2.9
incentive
0.8

Our algorithm analyzes dozens of metrics to generate these 8 key vulnerability categories, which are then combined to calculate the overall risk score.