CVE-2025-55074: Github.com/mattermost/mattermost server Mattermost Allows Other Users To Vulnerability

LOW
Advisory Identifier: GHSA-9hh7-6558-qfp2
CVSS 3.0
CWE-276
Published
Advisory Summary

CVE-2025-55074 is a LOW (CVSS 3.0) mattermost allows other users to vulnerability (CWE-276: Incorrect Default Permissions) affecting Github.com/mattermost/mattermost server libraries in the Go ecosystem. The issue involves mattermost allows other users to determine when users had read channels via channel member objects. Remediation is available by upgrading affected packages to version 10.11.4, 10.5.12, 8.0.0-20250905150616-ba86dfc5876b6.

CVE-2025-55074 at a Glance

CVE Identifier CVE-2025-55074
GHSA Identifier GHSA-9hh7-6558-qfp2
Severity LOW
CVSS v3.1 Base Score 3.0
CWE Classification CWE-276: Incorrect Default Permissions
Affected Product Github.com/mattermost/mattermost server
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 3.0

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:R/S:C/C:L/I:N/A:N).

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

How to Fix CVE-2025-55074

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: 10.11.4
Upgrade github.com/mattermost/mattermost-server to 10.11.4
github.com/mattermost/mattermost-server fixed: 10.5.12
Upgrade github.com/mattermost/mattermost-server to 10.5.12
github.com/mattermost/mattermost/server/v8 fixed: 8.0.0-20250905150616-ba86dfc5876b6
Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20250905150616-ba86dfc5876b6
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-2025-55074, 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 10.11.4), 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-276: Incorrect Default Permissions, where during installation, installed file permissions are set to allow anyone to modify those files. 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 10.11.x <= 10.11.3, and 10.5.x <= 10.5.11 fail to enforce access permissions on the Agents plugin which allows other users to determine when users had read channels via channel member objects.

CVE-2025-55074 Affected Github.com/mattermost/mattermost server Versions

3 component(s)
Fixed Versions:
10.11.410.5.128.0.0-20250905150616-ba86dfc5876b6
Product / Package Ecosystem Affected Versions Fixed Version
github.com/mattermost/mattermost-server
Go
≥ 10.11.0
< 10.11.4
10.11.4
github.com/mattermost/mattermost-server
Go
≥ 10.5.0
< 10.5.12
10.5.12
github.com/mattermost/mattermost/server/v8
Go
< 8.0.0-20250905150616-ba86dfc5876b6
8.0.0-20250905150616-ba86dfc5876b6

References

Frequently Asked Questions

What is CVE-2025-55074?
CVE-2025-55074 is a security vulnerability in Github.com/mattermost/mattermost server involving Mattermost allows other users to determine when users had read channels via channel member objects under CWE-276: Incorrect Default Permissions.
Which Github.com/mattermost/mattermost server versions are affected?
Affected versions include releases prior to 10.11.4, 10.5.12, 8.0.0-20250905150616-ba86dfc5876b6 across affected packages: github.com/mattermost/mattermost-server, github.com/mattermost/mattermost/server/v8.
What version fixes CVE-2025-55074?
Upgrading to 10.11.4, 10.5.12, 8.0.0-20250905150616-ba86dfc5876b6 (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 10.11.4, 10.5.12. Upgrade your dependency to 10.11.4, 10.5.12 or later.
Is github.com/mattermost/mattermost/server/v8 affected?
Yes, github.com/mattermost/mattermost/server/v8 is affected in releases prior to 8.0.0-20250905150616-ba86dfc5876b6. Upgrade your dependency to 8.0.0-20250905150616-ba86dfc5876b6 or later.
What is the CVSS score of CVE-2025-55074?
CVE-2025-55074 has a CVSS v3.1 base score of 3.0 (LOW) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:N/A:N.
What CWE is associated with CVE-2025-55074?
CVE-2025-55074 is classified under CWE-276: Incorrect Default Permissions (During installation, installed file permissions are set to allow anyone to modify those files.).
How can I check Go dependencies for CVE-2025-55074?
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-9hh7-6558-qfp2",
  "modified" : "2025-11-27T08:34:12Z",
  "published" : "2025-11-18T18:32:52Z",
  "aliases" : [ "CVE-2025-55074" ],
  "summary" : "Mattermost allows other users to determine when users had read channels via channel member objects",
  "details" : "Mattermost versions 10.11.x <= 10.11.3, and 10.5.x <= 10.5.11 fail to enforce access permissions on the Agents plugin which allows other users to determine when users had read channels via channel member objects.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.11.0"
      }, {
        "fixed" : "10.11.4"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.5.0"
      }, {
        "fixed" : "10.5.12"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost/server/v8"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "8.0.0-20250905150616-ba86dfc5876b6"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-55074"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/pull/33835"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/pull/33905"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/98acefe911dd9de7edf47a7d825dd99f53141a52"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/ba86dfc5876b354b9d3c20ff45c08ca6f8426149"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/d72d437f1567ba0b639b6e4fd73bab06c51baab5"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-9hh7-6558-qfp2"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mattermost/mattermost"
  }, {
    "type" : "WEB",
    "url" : "https://mattermost.com/security-updates"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-276" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-11-18T21:03:28Z",
    "nvd_published_at" : "2025-11-18T16:15:44Z"
  }
}