CVE-2025-14350: Github.com/mattermost/mattermost/server/v8 Mattermost Fails To Properly Validate Vulnerability

MODERATE
Advisory Identifier: GHSA-57cc-2pf4-mhmx
Share
CVSS 4.3
CWE-862
Published
Advisory Summary

CVE-2025-14350 is a MODERATE (CVSS 4.3) mattermost fails to properly validate vulnerability (CWE-862: Missing Authorization) affecting Github.com/mattermost/mattermost/server/v8 libraries in the Go ecosystem. The issue involves mattermost fails to properly validate team membership when processing channel mentions. Remediation is available by upgrading affected packages to version 8.0.0-20251209134645-761e56bb11cc, 5.3.2-0.20251209134645-761e56bb11cc.

CVE-2025-14350 at a Glance

CVE Identifier CVE-2025-14350
GHSA Identifier GHSA-57cc-2pf4-mhmx
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-862: Missing Authorization
Affected Product Github.com/mattermost/mattermost/server/v8
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 4.3

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

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
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-2025-14350

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: 8.0.0-20251209134645-761e56bb11cc 
Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20251209134645-761e56bb11cc
github.com/mattermost/mattermost-server fixed: Latest secure release 
Upgrade github.com/mattermost/mattermost-server to Latest secure release
github.com/mattermost/mattermost-server fixed: Latest secure release 
Upgrade github.com/mattermost/mattermost-server to Latest secure release
github.com/mattermost/mattermost-server fixed: Latest secure release 
Upgrade github.com/mattermost/mattermost-server to Latest secure release
github.com/mattermost/mattermost-server fixed: 5.3.2-0.20251209134645-761e56bb11cc 
Upgrade github.com/mattermost/mattermost-server to 5.3.2-0.20251209134645-761e56bb11cc
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-2025-14350, 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 8.0.0-20251209134645-761e56bb11cc), 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-862: Missing Authorization, where the product does not perform an authorization check when an actor attempts to access a resource or perform an action. 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 11.1.x <= 11.1.2, 10.11.x <= 10.11.9, 11.2.x <= 11.2.1 fail to properly validate team membership when processing channel mentions which allows authenticated users to determine the existence of teams and their URL names via posting channel shortlinks and observing the channel_mentions property in the API response. Mattermost Advisory ID: MMSA-2025-00563

CVE-2025-14350 Affected Github.com/mattermost/mattermost/server/v8 Versions

5 component(s)
Fixed Versions:
8.0.0-20251209134645-761e56bb11cc5.3.2-0.20251209134645-761e56bb11cc
Product / Package Ecosystem Affected Versions Fixed Version
github.com/mattermost/mattermost/server/v8
golang/github.com/mattermost/mattermost/server/v8
Go
< 8.0.0-20251209134645-761e56bb11cc
8.0.0-20251209134645-761e56bb11cc
github.com/mattermost/mattermost-server
golang/github.com/mattermost/mattermost-server
Go
≥ 11.1.0
github.com/mattermost/mattermost-server
golang/github.com/mattermost/mattermost-server
Go
≥ 10.11.0
github.com/mattermost/mattermost-server
golang/github.com/mattermost/mattermost-server
Go
≥ 11.2.0
github.com/mattermost/mattermost-server
golang/github.com/mattermost/mattermost-server
Go
< 5.3.2-0.20251209134645-761e56bb11cc
5.3.2-0.20251209134645-761e56bb11cc

References

NVD — CVE-2025-14350 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-14350
Security Fix Commit FIX COMMIT
https://github.com/mattermost/mattermost/commit/761e56bb11ccb751ddbe4bab5898ccc2b384fd82
Github.com/mattermost/mattermost/server/v8 Source Repository REPOSITORY
https://github.com/mattermost/mattermost
Github.com/mattermost/mattermost/server/v8 Security Information SECURITY
https://mattermost.com/security-updates

Frequently Asked Questions

What is CVE-2025-14350?
CVE-2025-14350 is a security vulnerability in Github.com/mattermost/mattermost/server/v8 involving Mattermost fails to properly validate team membership when processing channel mentions under CWE-862: Missing Authorization.
Which Github.com/mattermost/mattermost/server/v8 versions are affected?
Affected versions include releases prior to 8.0.0-20251209134645-761e56bb11cc, 5.3.2-0.20251209134645-761e56bb11cc across affected packages: github.com/mattermost/mattermost/server/v8, github.com/mattermost/mattermost-server.
What version fixes CVE-2025-14350?
Upgrading to 8.0.0-20251209134645-761e56bb11cc, 5.3.2-0.20251209134645-761e56bb11cc (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 8.0.0-20251209134645-761e56bb11cc. Upgrade your dependency to 8.0.0-20251209134645-761e56bb11cc or later.
Is github.com/mattermost/mattermost-server affected?
Yes, github.com/mattermost/mattermost-server is affected in releases prior to Latest secure release, 5.3.2-0.20251209134645-761e56bb11cc. Upgrade your dependency to Latest secure release, 5.3.2-0.20251209134645-761e56bb11cc or later.
What is the CVSS score of CVE-2025-14350?
CVE-2025-14350 has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2025-14350?
CVE-2025-14350 is classified under CWE-862: Missing Authorization (The product does not perform an authorization check when an actor attempts to access a resource or perform an action.).
How can I check Go dependencies for CVE-2025-14350?
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
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-57cc-2pf4-mhmx",
  "modified" : "2026-02-19T19:35:24Z",
  "published" : "2026-02-16T15:32:47Z",
  "aliases" : [ "CVE-2025-14350" ],
  "summary" : "Mattermost fails to properly validate team membership when processing channel mentions",
  "details" : "Mattermost versions 11.1.x <= 11.1.2, 10.11.x <= 10.11.9, 11.2.x <= 11.2.1 fail to properly validate team membership when processing channel mentions which allows authenticated users to determine the existence of teams and their URL names via posting channel shortlinks and observing the channel_mentions property in the API response. Mattermost Advisory ID: MMSA-2025-00563",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/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" : "8.0.0-20251209134645-761e56bb11cc"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.1.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "< 11.1.3"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.11.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "< 10.11.10"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.2.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "< 11.2.2"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.3.2-0.20251209134645-761e56bb11cc"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-14350"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/761e56bb11ccb751ddbe4bab5898ccc2b384fd82"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mattermost/mattermost"
  }, {
    "type" : "WEB",
    "url" : "https://mattermost.com/security-updates"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-862" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-19T19:35:24Z",
    "nvd_published_at" : "2026-02-16T13:15:59Z"
  }
}