CVE-2024-32939: Email addresses of remote users visible in props regardless of server settings

Severity: low (CVSS 3.7 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 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.x <= 9.10.0, 9.8.x <= 9.8.2, when shared channels are enabled, fail to redact remote users' original email addresses stored in user props when email addresses are otherwise configured not to be visible in the local server."

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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