CVE-2025-8402: Mattermost has Potential Server Crash due to Unvalidated Import Data

August 21, 2025 (updated August 22, 2025)

Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 9.11.x <= 9.11.17, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to validate import data which allows a system admin to crash the server via the bulk import feature.

References

github.com/advisories/GHSA-h469-4fcf-p23h
github.com/mattermost/mattermost
mattermost.com/security-updates
nvd.nist.gov/vuln/detail/CVE-2025-8402

Code Behaviors & Features

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