CVE-2026-3112: Mattermost allows system administrators to read arbitrary host files via malicious AdvancedLoggingJSON configuration

March 26, 2026 (updated March 31, 2026)

Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate Advanced Logging file target paths which allows system administrators to read arbitrary host files via malicious AdvancedLoggingJSON configuration in support packet generation. Mattermost Advisory ID: MMSA-2025-00562.

References

github.com/advisories/GHSA-3mw5-466q-295q
github.com/mattermost/mattermost
mattermost.com/security-updates
nvd.nist.gov/vuln/detail/CVE-2026-3112

Code Behaviors & Features

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