Privilege Escalation via Request Handling in Firefox 154 & Thunderbird 154
CVE-2026-74955 Published on August 18, 2026

Privilege escalation in the Request Handling component
Privilege escalation in the Request Handling component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.

NVD

Vulnerability Analysis

CVE-2026-74955 can be exploited with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
REQUIRED
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

Improper Privilege Management

The software does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.


Products Associated with CVE-2026-74955

stack.watch emails you whenever new vulnerabilities are published in Mozilla Firefox or Mozilla Thunderbird. Just hit a watch button to start following.

Mozilla Firefox
 
Mozilla Thunderbird
 

Affected Versions

Mozilla Firefox: Mozilla Thunderbird: