CVE-2024-42411: User creation date manipulation in POST /api/v4/users

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% 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-754

Description

Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0, 9.8.x <= 9.8.2 fail to restrict the input in POST /api/v4/users which allows a user to manipulate the creation date in POST /api/v4/users tricking the admin into believing their account is much older.

Affected products

Mattermost App Framework: from 9.5.0 before 9.5.8; from 9.8.0 before 9.8.3; from 9.9.0 before 9.9.2; from 9.10.0 before 9.10.1 — fixed in 9.10.1, 9.5.8, 9.8.3, 9.9.2

How to fix

Upgrade to a fixed version: Mattermost App Framework 9.10.1, 9.5.8, 9.8.3, 9.9.2. Check the vendor advisory for mitigations.

References

https://mattermost.com/security-updates

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