Mozilla Firefox and Thunderbird Privilege Escalation Vulnerability in Netmonitor Component

Vulnerability

A privilege escalation vulnerability has been identified in the Netmonitor component of Mozilla Firefox and Thunderbird. This issue affects Firefox versions prior to 148, Firefox ESR versions prior to 140.8, Thunderbird versions prior to 148, and Thunderbird ESR versions prior to 140.8. The vulnerability arises from incorrect handling of certain conditions, which could potentially be exploited to gain elevated privileges.

Impact

Exploitation of this vulnerability could lead to unauthorized privilege escalation, allowing a user to gain elevated rights or access within the application.

Remediation

Users can upgrade to Firefox 148, Thunderbird 148, Firefox ESR 140.8, or Thunderbird ESR 140.8 to address this vulnerability.

Added: Feb 24, 2026, 2:43 PM
Updated: Feb 24, 2026, 10:45 PM

Vulnerability Rating

Custom Algorithm
spread
8.4
impact
5.0
exploitability
3.3
remediation
7.7
relevance
3.1
threat
0.0
urgency
2.9
incentive
0.0

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