CVE-2025-64641: Mattermost doesn't verify that post actions invoking `/share-issue-publicly` were created by the Jira plugin

December 24, 2025 (updated December 26, 2025)

Mattermost versions 11.1.x <= 11.1.0, 11.0.x <= 11.0.5, 10.12.x <= 10.12.3, 10.11.x <= 10.11.7 fail to verify that post actions invoking /share-issue-publicly were created by the Jira plugin which allowed a malicious Mattermost user to exfiltrate Jira tickets when victim users interacted with affected posts

References

github.com/advisories/GHSA-vww6-79rv-3j4x
github.com/mattermost/mattermost
github.com/mattermost/mattermost/commit/b57c297c6d7ae6812d85e32a625806ac9555deee
github.com/mattermost/mattermost/pull/34551
mattermost.com/security-updates
nvd.nist.gov/vuln/detail/CVE-2025-64641

Code Behaviors & Features

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