# CVE-2025-62690: GO-2025-4248 - Mattermost has missing redirect URL validation in github.com/mattermost/mattermost

Source: https://junglewise.ai/threats/cve-2025-62690-mattermost-has-missing-redirect-url-validation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-12-17  
License: CC BY 4.0 with a link back

CVE-2025-62690 · Severity: low · CVSS 3.1 · Published 2025-12-17

Mattermost versions 10.11.x <= 10.11.4 fail to validate redirect URLs on the /error page, which allows an attacker to redirect a victim to a malicious site via a crafted link opened in a new tab.

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-2025-62690 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-62690 being exploited in the wild.

**How severe is CVE-2025-62690?** Low severity, with a CVSS score of 3.1, published 17 December 2025.

**Which products and versions are affected?** github.com/mattermost/mattermost (Go) SEMVER:introduced=10.11.0-rc1,fixed=10.11.5-0.20251016131338-dad6bd7a1509, SEMVER:introduced=10.11.0-rc1+incompatible,fixed=11.1.0+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-2025-62690?** Yes. github.com/mattermost/mattermost (Go): upgrade to 10.11.5-0.20251016131338-dad6bd7a1509, 11.1.0+incompatible or later; github.com/mattermost/mattermost/server/v8 (Go): upgrade to 8.0.0-20251016131338-dad6bd7a1509 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2025-62690?** 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 10.11.5-0.20251016131338-dad6bd7a1509, 11.1.0+incompatible or later

  ```sh
  go get github.com/mattermost/mattermost@v11.1.0+incompatible
  ```

- github.com/mattermost/mattermost/server/v8 (Go): upgrade to 8.0.0-20251016131338-dad6bd7a1509 or later

  ```sh
  go get github.com/mattermost/mattermost/server/v8@v8.0.0-20251016131338-dad6bd7a1509
  ```


## Affected products

- github.com/mattermost/mattermost (Go) SEMVER:introduced=10.11.0-rc1,fixed=10.11.5-0.20251016131338-dad6bd7a1509, SEMVER:introduced=10.11.0-rc1+incompatible,fixed=11.1.0+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=8.0.0-20250721062209-4952acea88ce,fixed=8.0.0-20251016131338-dad6bd7a1509
- Mattermost Server

## Identifiers

- CVE-2025-62690
- GHSA-q66g-q98c-q454
- GO-2025-4248

## Related threats

- [Mattermost CSRF via Agents plugin mention reminder validation](https://junglewise.ai/threats/cve-2026-93851-mattermost-versions-11-9-x-11-9-1-11-8-x-11-8-5-11-7-x-11-7-10)
- [Mattermost denial of service via PDF text extraction memory exhaustion](https://junglewise.ai/threats/cve-2026-93850-mattermost-versions-11-9-x-11-9-1-11-8-x-11-8-5-11-7-x-11-7-10-11)
- [Mattermost denial of service in WebSocket msgpack decoder](https://junglewise.ai/threats/cve-2026-93849-mattermost-versions-11-9-x-11-9-1-11-8-x-11-8-5-11-7-x-11-7-10-11)
- [Mattermost information disclosure in post deletion events](https://junglewise.ai/threats/cve-2026-19621-mattermost-versions-11-10-x-11-10-0-11-7-x-11-7-9-11-9-x-11-9-1)
- [Mattermost authentication token leak in server logs](https://junglewise.ai/threats/cve-2026-19600-mattermost-versions-11-9-x-11-9-1-11-8-x-11-8-5-11-7-x-11-7-10-11)