CVE-2026-3115

Description

A flaw was found in Mattermost. Authenticated guest users can exploit this vulnerability by retrieving group member IDs through the group retrieval endpoint. This failure to apply view restrictions allows them to enumerate user IDs that are outside their permitted visibility scope, leading to information disclosure.

Statement

Red Hat Product Security has determined that this vulnerability does not affect any currently supported Red Hat product. This assessment may evolve based on further analysis and discovery. For more information about this vulnerability and the products it affects, please see the linked references.

Understanding the Weakness (CWE)

Access Control

Technical Impact: Bypass Protection Mechanism

Access control checks for specific user data or functionality can be bypassed.

Access Control

Technical Impact: Gain Privileges or Assume Identity

Horizontal escalation of privilege is possible (one user can view/modify information of another user).

Access Control

Technical Impact: Gain Privileges or Assume Identity

Vertical escalation of privilege is possible if the user-controlled key is actually a flag that indicates administrator status, allowing the attacker to gain administrative access.

Frequently Asked Questions

Want to get errata notifications? Sign up here.