CVE-2025-53971: Github.com/mattermost/mattermost server Mattermost Fails To Properly Validate Vulnerability

LOW
Advisory Identifier: GHSA-4276-cm8c-788h
CVSS 3.8
CWE-863
Published
Advisory Summary

CVE-2025-53971 is a LOW (CVSS 3.8) mattermost fails to properly validate vulnerability (CWE-863: Incorrect Authorization) affecting Github.com/mattermost/mattermost server libraries in the Go ecosystem. The issue involves mattermost fails to properly validate team role modification. Remediation is available by upgrading affected packages to version 10.5.9, 9.11.18, 8.0.0-20250721095846-c602a4a78e1f.

CVE-2025-53971 at a Glance

CVE Identifier CVE-2025-53971
GHSA Identifier GHSA-4276-cm8c-788h
Severity LOW
CVSS v3.1 Base Score 3.8
CWE Classification CWE-863: Incorrect Authorization
Affected Product Github.com/mattermost/mattermost server
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 3.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required High (PR:H)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2025-53971

To remediate this vulnerability, upgrade all affected Github.com/mattermost/mattermost server dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/mattermost/mattermost-server fixed: 10.5.9
Upgrade github.com/mattermost/mattermost-server to 10.5.9
github.com/mattermost/mattermost-server fixed: 9.11.18
Upgrade github.com/mattermost/mattermost-server to 9.11.18
github.com/mattermost/mattermost/server/v8 fixed: 8.0.0-20250721095846-c602a4a78e1f
Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20250721095846-c602a4a78e1f
github.com/mattermost/mattermost-server/v5 fixed: Latest secure release
Upgrade github.com/mattermost/mattermost-server/v5 to Latest secure release
github.com/mattermost/mattermost-server/v6 fixed: Latest secure release
Upgrade github.com/mattermost/mattermost-server/v6 to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for github.com/mattermost/mattermost-server

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-53971, inspect your project dependencies for Github.com/mattermost/mattermost server:

inspect dependencies for github.com/mattermost/mattermost-server

Analyze the terminal output to locate any version of Github.com/mattermost/mattermost server in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 10.5.9), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-863: Incorrect Authorization, where 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. In Github.com/mattermost/mattermost server, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Mattermost versions 10.5.x <= 10.5.8, 9.11.x <= 9.11.17 fail to properly validate authorization for team scheme role modifications which allows Team Admins to demote Team Members to Guests via the PUT /api/v4/teams/team-id/members/user-id/schemeRoles API endpoint.

CVE-2025-53971 Affected Github.com/mattermost/mattermost server Versions

5 component(s)
Fixed Versions:
10.5.99.11.188.0.0-20250721095846-c602a4a78e1f
Product / Package Ecosystem Affected Versions Fixed Version
github.com/mattermost/mattermost-server
Go
≥ 10.5.0
< 10.5.9
10.5.9
github.com/mattermost/mattermost-server
Go
≥ 9.11.0
< 9.11.18
9.11.18
github.com/mattermost/mattermost/server/v8
Go
< 8.0.0-20250721095846-c602a4a78e1f
8.0.0-20250721095846-c602a4a78e1f
github.com/mattermost/mattermost-server/v5
Go
≤ 5.39.3
github.com/mattermost/mattermost-server/v6
Go
≤ 6.7.2

References

Frequently Asked Questions

What is CVE-2025-53971?
CVE-2025-53971 is a security vulnerability in Github.com/mattermost/mattermost server involving Mattermost Fails to Properly Validate Team Role Modification under CWE-863: Incorrect Authorization.
Which Github.com/mattermost/mattermost server versions are affected?
Affected versions include releases prior to 10.5.9, 9.11.18, 8.0.0-20250721095846-c602a4a78e1f across affected packages: github.com/mattermost/mattermost-server, github.com/mattermost/mattermost/server/v8, github.com/mattermost/mattermost-server/v5, github.com/mattermost/mattermost-server/v6.
What version fixes CVE-2025-53971?
Upgrading to 10.5.9, 9.11.18, 8.0.0-20250721095846-c602a4a78e1f (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/mattermost/mattermost-server affected?
Yes, github.com/mattermost/mattermost-server is affected in releases prior to 10.5.9, 9.11.18. Upgrade your dependency to 10.5.9, 9.11.18 or later.
Is github.com/mattermost/mattermost/server/v8 affected?
Yes, github.com/mattermost/mattermost/server/v8 is affected in releases prior to 8.0.0-20250721095846-c602a4a78e1f. Upgrade your dependency to 8.0.0-20250721095846-c602a4a78e1f or later.
What is the CVSS score of CVE-2025-53971?
CVE-2025-53971 has a CVSS v3.1 base score of 3.8 (LOW) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N.
What CWE is associated with CVE-2025-53971?
CVE-2025-53971 is classified under CWE-863: Incorrect Authorization (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.).
How can I check Go dependencies for CVE-2025-53971?
Run the dependency tree command: 'inspect dependencies for github.com/mattermost/mattermost-server'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-4276-cm8c-788h",
  "modified" : "2025-08-29T20:57:09Z",
  "published" : "2025-08-21T09:30:21Z",
  "aliases" : [ "CVE-2025-53971" ],
  "summary" : "Mattermost Fails to Properly Validate Team Role Modification",
  "details" : "Mattermost versions 10.5.x <= 10.5.8, 9.11.x <= 9.11.17 fail to properly validate authorization for team scheme role modifications which allows Team Admins to demote Team Members to Guests via the PUT /api/v4/teams/team-id/members/user-id/schemeRoles API endpoint.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.5.0"
      }, {
        "fixed" : "10.5.9"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.5.8"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.11.0"
      }, {
        "fixed" : "9.11.18"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 9.11.17"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost/server/v8"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "8.0.0-20250721095846-c602a4a78e1f"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server/v5"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "5.39.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server/v6"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "6.7.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-53971"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mattermost/mattermost"
  }, {
    "type" : "WEB",
    "url" : "https://mattermost.com/security-updates"
  }, {
    "type" : "WEB",
    "url" : "https://pkg.go.dev/vuln/GO-2025-3902"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-08-21T16:03:01Z",
    "nvd_published_at" : "2025-08-21T08:15:30Z"
  }
}