Guest User Permission Flaw in Mattermost Software
CVE-2025-41443

4.3MEDIUM

Key Information:

Vendor

Mattermost
Status
Mattermost
Vendor
CVE Published:
16 October 2025

What is CVE-2025-41443?

A vulnerability exists in Mattermost software that allows guest users to bypass intended access controls, potentially leading to unauthorized discovery of public channels and their associated metadata. Specifically, certain versions of Mattermost fail to properly validate guest user permissions when accessing channel data through the API endpoint. This flaw may expose sensitive information about active public channels to unauthorized users.

Affected Version(s)

Mattermost 10.5.0 <= 10.5.10

Mattermost 10.11.0 <= 10.11.2

Mattermost 10.12.0

References

https://mattermost.com/security-updates

CVSS V3.1

Score:
4.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

lordwillmore
JSON
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CVE-2025-41443 : Guest User Permission Flaw in Mattermost Software