CVE-2024-41926: Github.com/mattermost/mattermost/server/v8 Mattermost Allows Remote Actor To set Vulnerability

MODERATE
Advisory Identifier: GHSA-9fpw-c9x7-cv3j
CVSS 2.7
CWE-284 CWE-346
Published
Advisory Summary

CVE-2024-41926 is a MODERATE (CVSS 2.7) mattermost allows remote actor to set vulnerability (CWE-284: Improper Access Control) affecting Github.com/mattermost/mattermost/server/v8 libraries in the Go ecosystem. The issue involves mattermost allows remote actor to set arbitrary remoteid values for synced users. Remediation is available by upgrading affected packages to version 9.5.7, 9.9.1, 8.0.0-20240604093018-5114c3b7cdb8, 5.3.2-0.20240604093018-5114c3b7cdb8.

CVE-2024-41926 at a Glance

CVE Identifier CVE-2024-41926
GHSA Identifier GHSA-9fpw-c9x7-cv3j
Severity MODERATE
CVSS v3.1 Base Score 2.7
CWE Classification CWE-284: Improper Access Control
Affected Product Github.com/mattermost/mattermost/server/v8
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 2.7

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:N/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 None (C:N)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2024-41926

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: 9.5.7
Upgrade github.com/mattermost/mattermost/server/v8 to 9.5.7
github.com/mattermost/mattermost/server/v8 fixed: 9.9.1
Upgrade github.com/mattermost/mattermost/server/v8 to 9.9.1
github.com/mattermost/mattermost/server/v8 fixed: 8.0.0-20240604093018-5114c3b7cdb8
Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20240604093018-5114c3b7cdb8
github.com/mattermost/mattermost fixed: 5.3.2-0.20240604093018-5114c3b7cdb8
Upgrade github.com/mattermost/mattermost to 5.3.2-0.20240604093018-5114c3b7cdb8
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-2024-41926, 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 9.5.7), 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-284: Improper Access Control, where the product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. 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 9.9.x <= 9.9.0 and 9.5.x <= 9.5.6 fail to validate the source of sync messages and only allow the correct remote IDs, which allows a malicious remote to set arbitrary RemoteId values for synced users and therefore claim that a user was synced from another remote.

CVE-2024-41926 Affected Github.com/mattermost/mattermost/server/v8 Versions

4 component(s)
Fixed Versions:
9.5.79.9.18.0.0-20240604093018-5114c3b7cdb85.3.2-0.20240604093018-5114c3b7cdb8
Product / Package Ecosystem Affected Versions Fixed Version
github.com/mattermost/mattermost/server/v8
Go
≥ 9.5.0
< 9.5.7
9.5.7
github.com/mattermost/mattermost/server/v8
Go
≥ 9.9.0
< 9.9.1
All 1 versions
9.9.0
9.9.1
github.com/mattermost/mattermost/server/v8
Go
< 8.0.0-20240604093018-5114c3b7cdb8
8.0.0-20240604093018-5114c3b7cdb8
github.com/mattermost/mattermost
Go
< 5.3.2-0.20240604093018-5114c3b7cdb8
5.3.2-0.20240604093018-5114c3b7cdb8

References

Frequently Asked Questions

What is CVE-2024-41926?
CVE-2024-41926 is a security vulnerability in Github.com/mattermost/mattermost/server/v8 involving Mattermost allows remote actor to set arbitrary RemoteId values for synced users under CWE-284: Improper Access Control.
Which Github.com/mattermost/mattermost/server/v8 versions are affected?
Affected versions include releases prior to 9.5.7, 9.9.1, 8.0.0-20240604093018-5114c3b7cdb8, 5.3.2-0.20240604093018-5114c3b7cdb8 across affected packages: github.com/mattermost/mattermost/server/v8, github.com/mattermost/mattermost.
What version fixes CVE-2024-41926?
Upgrading to 9.5.7, 9.9.1, 8.0.0-20240604093018-5114c3b7cdb8, 5.3.2-0.20240604093018-5114c3b7cdb8 (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 9.5.7, 9.9.1, 8.0.0-20240604093018-5114c3b7cdb8. Upgrade your dependency to 9.5.7, 9.9.1, 8.0.0-20240604093018-5114c3b7cdb8 or later.
Is github.com/mattermost/mattermost affected?
Yes, github.com/mattermost/mattermost is affected in releases prior to 5.3.2-0.20240604093018-5114c3b7cdb8. Upgrade your dependency to 5.3.2-0.20240604093018-5114c3b7cdb8 or later.
What is the CVSS score of CVE-2024-41926?
CVE-2024-41926 has a CVSS v3.1 base score of 2.7 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N.
What CWE is associated with CVE-2024-41926?
CVE-2024-41926 is classified under CWE-284: Improper Access Control (The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.).
How can I check Go dependencies for CVE-2024-41926?
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-9fpw-c9x7-cv3j",
  "modified" : "2025-07-09T16:41:20Z",
  "published" : "2024-08-01T15:32:23Z",
  "aliases" : [ "CVE-2024-41926" ],
  "summary" : "Mattermost allows remote actor to set arbitrary RemoteId values for synced users",
  "details" : "Mattermost versions 9.9.x <= 9.9.0 and 9.5.x <= 9.5.6 fail to validate the source of sync messages and only allow the correct remote IDs, which allows a malicious remote to set arbitrary RemoteId values for synced users and therefore claim that a user was synced from another remote.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost/server/v8"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.5.0"
      }, {
        "fixed" : "9.5.7"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost/server/v8"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.9.0"
      }, {
        "fixed" : "9.9.1"
      } ]
    } ],
    "versions" : [ "9.9.0" ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost/server/v8"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "8.0.0-20240604093018-5114c3b7cdb8"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.3.2-0.20240604093018-5114c3b7cdb8"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-41926"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/5114c3b7cdb84086959bf0ef8bc5afdaedf9fef6"
  }, {
    "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-2024-3022"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-284", "CWE-346" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-08-02T01:19:49Z",
    "nvd_published_at" : "2024-08-01T15:15:13Z"
  }
}