# CVE-2026-26304: Mattermost fails to verify run_create permission for empty playbookId

Source: https://junglewise.ai/threats/cve-2026-26304-mattermost-fails-to-verify-run-create-permission-for-empty  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-03-23  
License: CC BY 4.0 with a link back

CVE-2026-26304 · Severity: low · CVSS 3.1 · Published 2026-03-23

Mattermost fails to verify run_create permission for empty playbookId in github.com/mattermost/mattermost-plugin-playbooks

Technologies: [github.com/mattermost/mattermost-plugin-playbooks (Go)](https://junglewise.ai/threats/technologies/github-com-mattermost-mattermost-plugin-playbooks). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-26304 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-26304 being exploited in the wild.

**How severe is CVE-2026-26304?** Low severity, with a CVSS score of 3.1, published 23 March 2026.

**Which products and versions are affected?** github.com/mattermost/mattermost-plugin-playbooks (Go) SEMVER:introduced=0,fixed=1.41.1-0.20260316224925-705f54a81841.

**Is there a fix for CVE-2026-26304?** Yes. github.com/mattermost/mattermost-plugin-playbooks (Go): upgrade to 1.41.1-0.20260316224925-705f54a81841 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-26304?** Check whether you run github.com/mattermost/mattermost-plugin-playbooks (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/mattermost/mattermost-plugin-playbooks (Go): upgrade to 1.41.1-0.20260316224925-705f54a81841 or later

  ```sh
  go get github.com/mattermost/mattermost-plugin-playbooks@v1.41.1-0.20260316224925-705f54a81841
  ```


## Affected products

- github.com/mattermost/mattermost-plugin-playbooks (Go) SEMVER:introduced=0,fixed=1.41.1-0.20260316224925-705f54a81841

## Identifiers

- CVE-2026-26304
- GHSA-4pmx-622h-x359
- GO-2026-4812

## Related threats

- [Mattermost Incorrect Authorization in Playbooks via /get endpoint](https://junglewise.ai/threats/cve-2026-6343-mattermost-incorrect-authorization-in-playbooks-via-get-endpoint)
- [Mattermost incorrect authorization in Playbook team updates](https://junglewise.ai/threats/cve-2026-4286-mattermost-incorrect-authorization-in-playbook-team-updates)
- [GO-2025-3644 - Mattermost Playbooks fails to properly validate permissions in github.com/mattermost/mattermost-plugin-playbooks](https://junglewise.ai/threats/cve-2025-41423-mattermost-playbooks-fails-to-properly-validate-permissions)
- [Mattermost Playbooks fails to properly validate the props used by the RetrospectivePost custom post type](https://junglewise.ai/threats/cve-2025-41395-mattermost-playbooks-fails-to-properly-validate-the-props-used-by)
- [Mattermost Playbooks fails to validate the uniqueness and quantity of task actions](https://junglewise.ai/threats/cve-2025-35965-mattermost-playbooks-fails-to-validate-the-uniqueness-and)