CVE-2025-6465: Github.com/mattermost/mattermost server Mattermost Fails To Sanitize File Vulnerability

MODERATE
Advisory Identifier: GHSA-pj6f-rc94-gw53
CVSS 4.3
CWE-22
Published
Advisory Summary

CVE-2025-6465 is a MODERATE (CVSS 4.3) mattermost fails to sanitize file vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Github.com/mattermost/mattermost server libraries in the Go ecosystem. The issue involves mattermost fails to sanitize file names. Remediation is available by upgrading affected packages to version 10.8.4, 10.5.9, 10.9.4, 10.10.1, 8.0.0-20250708173752-d6b35c41f0ae5.

CVE-2025-6465 at a Glance

CVE Identifier CVE-2025-6465
GHSA Identifier GHSA-pj6f-rc94-gw53
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product Github.com/mattermost/mattermost server
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:N/I:L/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 None (C:N)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2025-6465

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: 10.8.4
Upgrade github.com/mattermost/mattermost-server to 10.8.4
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: 10.9.4
Upgrade github.com/mattermost/mattermost-server to 10.9.4
github.com/mattermost/mattermost-server fixed: 10.10.1
Upgrade github.com/mattermost/mattermost-server to 10.10.1
github.com/mattermost/mattermost/server/v8 fixed: 8.0.0-20250708173752-d6b35c41f0ae5
Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20250708173752-d6b35c41f0ae5
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-2025-6465, 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 10.8.4), 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-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. 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 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to sanitize file names which allows users with file upload permission to overwrite file attachment thumbnails via path traversal in file streaming APIs.

CVE-2025-6465 Affected Github.com/mattermost/mattermost server Versions

5 component(s)
Fixed Versions:
10.8.410.5.910.9.410.10.18.0.0-20250708173752-d6b35c41f0ae5
Product / Package Ecosystem Affected Versions Fixed Version
github.com/mattermost/mattermost-server
Go
≥ 10.8.0
< 10.8.4
10.8.4
github.com/mattermost/mattermost-server
Go
≥ 10.5.0
< 10.5.9
10.5.9
github.com/mattermost/mattermost-server
Go
≥ 10.9.0
< 10.9.4
10.9.4
github.com/mattermost/mattermost-server
Go
≥ 10.10.0
< 10.10.1
All 1 versions
10.10.0
10.10.1
github.com/mattermost/mattermost/server/v8
Go
< 8.0.0-20250708173752-d6b35c41f0ae5
8.0.0-20250708173752-d6b35c41f0ae5

References

Frequently Asked Questions

What is CVE-2025-6465?
CVE-2025-6465 is a security vulnerability in Github.com/mattermost/mattermost server involving Mattermost Fails to Sanitize File Names under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which Github.com/mattermost/mattermost server versions are affected?
Affected versions include releases prior to 10.8.4, 10.5.9, 10.9.4, 10.10.1, 8.0.0-20250708173752-d6b35c41f0ae5 across affected packages: github.com/mattermost/mattermost-server, github.com/mattermost/mattermost/server/v8.
What version fixes CVE-2025-6465?
Upgrading to 10.8.4, 10.5.9, 10.9.4, 10.10.1, 8.0.0-20250708173752-d6b35c41f0ae5 (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 10.8.4, 10.5.9, 10.9.4, 10.10.1. Upgrade your dependency to 10.8.4, 10.5.9, 10.9.4, 10.10.1 or later.
Is github.com/mattermost/mattermost/server/v8 affected?
Yes, github.com/mattermost/mattermost/server/v8 is affected in releases prior to 8.0.0-20250708173752-d6b35c41f0ae5. Upgrade your dependency to 8.0.0-20250708173752-d6b35c41f0ae5 or later.
What is the CVSS score of CVE-2025-6465?
CVE-2025-6465 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:N/I:L/A:N.
What CWE is associated with CVE-2025-6465?
CVE-2025-6465 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.).
How can I check Go dependencies for CVE-2025-6465?
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-pj6f-rc94-gw53",
  "modified" : "2025-08-29T21:00:27Z",
  "published" : "2025-08-21T18:31:29Z",
  "aliases" : [ "CVE-2025-6465" ],
  "summary" : "Mattermost Fails to Sanitize File Names",
  "details" : "Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to sanitize file names which allows users with file upload permission to overwrite file attachment thumbnails via path traversal in file streaming APIs.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.8.0"
      }, {
        "fixed" : "10.8.4"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.8.3"
    }
  }, {
    "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" : "10.9.0"
      }, {
        "fixed" : "10.9.4"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.9.3"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.10.0"
      }, {
        "fixed" : "10.10.1"
      } ]
    } ],
    "versions" : [ "10.10.0" ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost/server/v8"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "8.0.0-20250708173752-d6b35c41f0ae5"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-6465"
  }, {
    "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-2025-3906"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-08-22T16:58:51Z",
    "nvd_published_at" : "2025-08-21T17:15:32Z"
  }
}