Firefox 151 WebExt Spoofing Vulnerability
CVE-2026-8960 Published on May 19, 2026

Spoofing issue in WebExtensions
Spoofing issue in WebExtensions. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

NVD

Vulnerability Analysis

CVE-2026-8960 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity, and no impact on availability.

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

Weakness Type

Authentication Bypass by Spoofing

This attack-focused weakness is caused by improperly implemented authentication schemes that are subject to spoofing attacks.


Products Associated with CVE-2026-8960

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Mozilla Firefox
 
Mozilla Thunderbird
 

Affected Versions

Mozilla Firefox: Mozilla Thunderbird:

Exploit Probability

EPSS
0.04%
Percentile
11.35%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.