# CVE-2025-13870: GO-2025-4178 - Mattermost fails to validate user permissions in Boards in github.com/mattermost/mattermost

Source: https://junglewise.ai/threats/cve-2025-13870-mattermost-fails-to-validate-user-permissions-in-boards  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-12-02  
License: CC BY 4.0 with a link back

CVE-2025-13870 · Severity: low · CVSS 3.1 · Published 2025-12-02

Mattermost versions 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to validate the user permission when accessing the files and subscribing to the block in Boards, which allows an authenticated user to access other board files and was able to subscribe to the block from other boards that the user does not have access to

Technologies: [github.com/mattermost/mattermost (Go)](https://junglewise.ai/threats/technologies/github-com-mattermost-mattermost), [github.com/mattermost/mattermost-server (Go)](https://junglewise.ai/threats/technologies/github-com-mattermost-mattermost-server), [github.com/mattermost/mattermost-server/v5 (Go)](https://junglewise.ai/threats/technologies/github-com-mattermost-mattermost-server-v5), [github.com/mattermost/mattermost-server/v6 (Go)](https://junglewise.ai/threats/technologies/github-com-mattermost-mattermost-server-v6), [github.com/mattermost/mattermost/server/v8 (Go)](https://junglewise.ai/threats/technologies/github-com-mattermost-mattermost-server-v8), [Mattermost Server](https://junglewise.ai/threats/technologies/server-public). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Mattermost](https://junglewise.ai/threats/vendors/mattermost).

## Quick answers

**Is CVE-2025-13870 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-13870 being exploited in the wild.

**How severe is CVE-2025-13870?** Low severity, with a CVSS score of 3.1, published 2 December 2025.

**Which products and versions are affected?** github.com/mattermost/mattermost (Go) SEMVER:introduced=10.11.0,fixed=10.11.5, SEMVER:introduced=10.5.0+incompatible,fixed=10.5.13+incompatible,introduced=10.11.0+incompatible,fixed=10.11.5+incompatible; github.com/mattermost/mattermost-server (Go) SEMVER:introduced=0; github.com/mattermost/mattermost-server/v5 (Go) SEMVER:introduced=0; github.com/mattermost/mattermost-server/v6 (Go) SEMVER:introduced=0; and 1 more.

**Is there a fix for CVE-2025-13870?** Yes. github.com/mattermost/mattermost (Go): upgrade to 10.11.5, 10.11.5+incompatible or later; github.com/mattermost/mattermost/server/v8 (Go): upgrade to 8.0.0-20250905150616-ba86dfc5876b, 8.0.0-20251212204551-54f2e9b4afd5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2025-13870?** Check whether you run github.com/mattermost/mattermost (Go), github.com/mattermost/mattermost-server (Go), github.com/mattermost/mattermost-server/v5 (Go) or one of the others listed 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 (Go): upgrade to 10.11.5, 10.11.5+incompatible or later

  ```sh
  go get github.com/mattermost/mattermost@v10.11.5+incompatible
  ```

- github.com/mattermost/mattermost/server/v8 (Go): upgrade to 8.0.0-20250905150616-ba86dfc5876b, 8.0.0-20251212204551-54f2e9b4afd5 or later

  ```sh
  go get github.com/mattermost/mattermost/server/v8@v8.0.0-20251212204551-54f2e9b4afd5
  ```


## Affected products

- github.com/mattermost/mattermost (Go) SEMVER:introduced=10.11.0,fixed=10.11.5, SEMVER:introduced=10.5.0+incompatible,fixed=10.5.13+incompatible,introduced=10.11.0+incompatible,fixed=10.11.5+incompatible
- github.com/mattermost/mattermost-server (Go) SEMVER:introduced=0
- github.com/mattermost/mattermost-server/v5 (Go) SEMVER:introduced=0
- github.com/mattermost/mattermost-server/v6 (Go) SEMVER:introduced=0
- github.com/mattermost/mattermost/server/v8 (Go) SEMVER:introduced=0,fixed=8.0.0-20250905150616-ba86dfc5876b, SEMVER:introduced=0,fixed=8.0.0-20251212204551-54f2e9b4afd5
- Mattermost Server

## Identifiers

- CVE-2025-13870
- GHSA-58w6-w55x-6wq8
- GO-2025-4178

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