Mattermost security updates 10.1.3 / 10.0.3 / 9.11.5 (ESR) / 9.5.13 (ESR) released

We’re informing you about a Mattermost security update, which addresses medium severity vulnerabilities. We highly recommend that you apply the update.

The security update is available for Mattermost dot releases 10.1.3, 10.0.3, 9.11.5 (Extended Support Release), and 9.5.13 (Extended Support Release), for both Team Edition and Enterprise Edition. They are available for download here.

Customer safety and data security are the utmost priorities for Mattermost. For our customers’ protection, and as outlined in our Responsible Disclosure policy, Mattermost does not disclose specifics on this vulnerability until 30 days after this announcement. After 30 days, we will publish specific details on the vulnerability on our Security Updates webpage.

The v10.1.3 version also includes the following fixes:

• Reverted a change enforcing usernames to start with alpha characters on the server MM-61143.
• Reverted a breaking change in registerSlashCommandWillBePostedHook that caused errors to surface in case an expected empty object was returned MM-61233.

The v9.11.5 and v9.5.13 versions also include the following fix:

• Pre-packaged Calls plugin v0.29.4.

You can follow the standard upgrade instructions to apply the updates