What’s Vulnerable › Vulnerabilities

CVE-2025-41436: Unauthorized access to archived channel content via threads interface

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-11-14 · updated 2026-10-19
• Weakness: CWE-863

Description

Mattermost versions <11.0 fail to properly enforce the "Allow users to view archived channels" setting which allows regular users to access archived channel content and files via the "Open in Channel" functionality from followed threads

Affected products

• Mattermost: before 11.0.0 — fixed in 11.0.0

How to fix

Upgrade to a fixed version: Mattermost 11.0.0. Check the vendor advisory for mitigations.

References

• https://mattermost.com/security-updates

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