CVE-2025-4128: Github.com/mattermost/mattermost/server/v8 Mattermost Allows Guest Users To Vulnerability

LOW
Advisory Identifier: GHSA-jwhw-xf5v-qgxc
CVSS 3.1
CWE-863
Published
Advisory Summary

CVE-2025-4128 is a LOW (CVSS 3.1) mattermost allows guest users to vulnerability (CWE-863: Incorrect Authorization) affecting Github.com/mattermost/mattermost/server/v8 libraries in the Go ecosystem. The issue involves mattermost allows guest users to view information about public teams they are not members of. Remediation is available by upgrading affected packages to version 8.0.0-20250422131222-701ddc896a10, 10.5.5, 9.11.14.

CVE-2025-4128 at a Glance

CVE Identifier CVE-2025-4128
GHSA Identifier GHSA-jwhw-xf5v-qgxc
Severity LOW
CVSS v3.1 Base Score 3.1
CWE Classification CWE-863: Incorrect Authorization
Affected Product Github.com/mattermost/mattermost/server/v8
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 3.1

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

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

How to Fix CVE-2025-4128

To remediate this vulnerability, upgrade all affected Github.com/mattermost/mattermost/server/v8 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/v8 fixed: 8.0.0-20250422131222-701ddc896a10
Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20250422131222-701ddc896a10
github.com/mattermost/mattermost-server fixed: 10.5.5
Upgrade github.com/mattermost/mattermost-server to 10.5.5
github.com/mattermost/mattermost-server fixed: 9.11.14
Upgrade github.com/mattermost/mattermost-server to 9.11.14
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/v8

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-4128, inspect your project dependencies for Github.com/mattermost/mattermost/server/v8:

inspect dependencies for github.com/mattermost/mattermost/server/v8

Analyze the terminal output to locate any version of Github.com/mattermost/mattermost/server/v8 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 8.0.0-20250422131222-701ddc896a10), 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/v8, 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 <= 10.5.4, 9.11.x <= 9.11.13 fail to properly restrict API access to team information, allowing guest users to bypass permissions and view information about public teams they are not members of via a direct API call to /api/v4/teams/{team_id}.

CVE-2025-4128 Affected Github.com/mattermost/mattermost/server/v8 Versions

3 component(s)
Fixed Versions:
8.0.0-20250422131222-701ddc896a1010.5.59.11.14
Product / Package Ecosystem Affected Versions Fixed Version
github.com/mattermost/mattermost/server/v8
Go
< 8.0.0-20250422131222-701ddc896a10
8.0.0-20250422131222-701ddc896a10
github.com/mattermost/mattermost-server
Go
≥ 10.5.0
< 10.5.5
10.5.5
github.com/mattermost/mattermost-server
Go
≥ 9.11.0
< 9.11.14
9.11.14

References

Frequently Asked Questions

What is CVE-2025-4128?
CVE-2025-4128 is a security vulnerability in Github.com/mattermost/mattermost/server/v8 involving Mattermost allows guest users to view information about public teams they are not members of under CWE-863: Incorrect Authorization.
Which Github.com/mattermost/mattermost/server/v8 versions are affected?
Affected versions include releases prior to 8.0.0-20250422131222-701ddc896a10, 10.5.5, 9.11.14 across affected packages: github.com/mattermost/mattermost/server/v8, github.com/mattermost/mattermost-server.
What version fixes CVE-2025-4128?
Upgrading to 8.0.0-20250422131222-701ddc896a10, 10.5.5, 9.11.14 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/mattermost/mattermost/server/v8 affected?
Yes, github.com/mattermost/mattermost/server/v8 is affected in releases prior to 8.0.0-20250422131222-701ddc896a10. Upgrade your dependency to 8.0.0-20250422131222-701ddc896a10 or later.
Is github.com/mattermost/mattermost-server affected?
Yes, github.com/mattermost/mattermost-server is affected in releases prior to 10.5.5, 9.11.14. Upgrade your dependency to 10.5.5, 9.11.14 or later.
What is the CVSS score of CVE-2025-4128?
CVE-2025-4128 has a CVSS v3.1 base score of 3.1 (LOW) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2025-4128?
CVE-2025-4128 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-2025-4128?
Run the dependency tree command: 'inspect dependencies for github.com/mattermost/mattermost/server/v8'. 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-jwhw-xf5v-qgxc",
  "modified" : "2025-06-11T15:44:39Z",
  "published" : "2025-06-11T12:30:36Z",
  "aliases" : [ "CVE-2025-4128" ],
  "summary" : "Mattermost allows guest users to view information about public teams they are not members of",
  "details" : "Mattermost versions 10.5.x <= 10.5.4, 9.11.x <= 9.11.13 fail to properly restrict API access to team information, allowing guest users to bypass permissions and view information about public teams they are not members of via a direct API call to /api/v4/teams/{team_id}.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost/server/v8"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "8.0.0-20250422131222-701ddc896a10"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.5.0"
      }, {
        "fixed" : "10.5.5"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.11.0"
      }, {
        "fixed" : "9.11.14"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-4128"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/2138a5f2ca6f75e2b99f6a04ea569d0f680c4fab"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/701ddc896a107b13f457fbdbe229bce5019fc516"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mattermost/mattermost"
  }, {
    "type" : "WEB",
    "url" : "https://mattermost.com/security-updates"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-06-11T15:44:39Z",
    "nvd_published_at" : "2025-06-11T11:15:23Z"
  }
}