CVE-2026-26304
Permission Bypass in Mattermost Playbook Run API Allows Unauthorized Run Creation
Publication date: 2026-03-16
Last updated on: 2026-03-18
Assigner: Mattermost, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| mattermost | mattermost_server | From 11.2.0 (inc) to 11.2.3 (exc) |
| mattermost | mattermost_server | From 11.3.0 (inc) to 11.3.1 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-863 | The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in Mattermost versions 11.3.x up to 11.3.0 and 11.2.x up to 11.2.2. It occurs because the software fails to verify the 'run_create' permission when the playbookId is empty. As a result, team members can create unauthorized runs using the playbook run API.
How can this vulnerability impact me? :
The impact of this vulnerability is that team members without proper authorization can create runs they should not be allowed to create. This could lead to unauthorized actions or changes within the Mattermost environment, potentially disrupting workflows or causing misuse of the playbook run functionality.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know