CVE-2024-43813: IDOR when marking read a user's channel

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: 2024-08-22 · updated 2026-06-17
Weakness: CWE-284

Description

Mattermost versions 9.5.x <= 9.5.7, 9.10.x <= 9.10.0 fail to enforce proper access controls which allows any authenticated user, including guests, to mark any channel inside any team as read for any user.

Affected products

Mattermost App Framework: from 9.5.0 before 9.5.8; from 9.10.0 before 9.10.1 — fixed in 9.10.1, 9.5.8

How to fix

Upgrade to a fixed version: Mattermost App Framework 9.10.1, 9.5.8. Check the vendor advisory for mitigations.

References

https://mattermost.com/security-updates

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