CVE-2025-55073: Github.com/mattermost/mattermost server Mattermost Allows An Attacker To Vulnerability

MODERATE
Advisory Identifier: GHSA-ff85-qw3h-g9vp
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CVSS 5.4
CWE-306
Published
Advisory Summary

CVE-2025-55073 is a MODERATE (CVSS 5.4) mattermost allows an attacker to vulnerability (CWE-306: Missing Authentication for Critical Function) affecting Github.com/mattermost/mattermost server libraries in the Go ecosystem. The issue involves mattermost allows an attacker to edit arbitrary posts via a crafted msteams plugin oauth redirect url. Remediation is available by upgrading affected packages to version 10.11.4, 10.5.12, 10.12.1, 8.0.0-20250929212932-a41db04d2746.

CVE-2025-55073 at a Glance

CVE Identifier CVE-2025-55073
GHSA Identifier GHSA-ff85-qw3h-g9vp
Severity MODERATE
CVSS v3.1 Base Score 5.4
CWE Classification CWE-306: Missing Authentication for Critical Function
Affected Product Github.com/mattermost/mattermost server
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 5.4

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:L).

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 Low (A:L)

How to Fix CVE-2025-55073

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 fixed: 10.12.1 
Upgrade github.com/mattermost/mattermost-server to 10.12.1
github.com/mattermost/mattermost/server/v8 fixed: 8.0.0-20250929212932-a41db04d2746 
Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20250929212932-a41db04d2746
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-2025-55073, 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-306: Missing Authentication for Critical Function, where the product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources. 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, 10.5.x <= 10.5.11, 10.12.x <= 10.12.0 fail to validate the relationship between the post being updated and the MSTeams plugin OAuth flow which allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL.

CVE-2025-55073 Affected Github.com/mattermost/mattermost server Versions

4 component(s)
Fixed Versions:
10.11.410.5.1210.12.18.0.0-20250929212932-a41db04d2746
Product / Package Ecosystem Affected Versions Fixed Version
github.com/mattermost/mattermost-server
golang/github.com/mattermost/mattermost-server
Go
≥ 10.11.0
< 10.11.4
10.11.4
github.com/mattermost/mattermost-server
golang/github.com/mattermost/mattermost-server
Go
≥ 10.5.0
< 10.5.12
10.5.12
github.com/mattermost/mattermost-server
golang/github.com/mattermost/mattermost-server
Go
≥ 10.12.0
< 10.12.1
10.12.1
github.com/mattermost/mattermost/server/v8
golang/github.com/mattermost/mattermost/server/v8
Go
< 8.0.0-20250929212932-a41db04d2746
8.0.0-20250929212932-a41db04d2746

References

NVD — CVE-2025-55073 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-55073
Security Fix Commit FIX COMMIT
https://github.com/mattermost/mattermost/commit/375ce229f4923205394d8f27925372b2cbf28130
Security Fix Commit FIX COMMIT
https://github.com/mattermost/mattermost/commit/6c288aa62bb3343183ec1d0a06360d14aa0193e9
Security Fix Commit FIX COMMIT
https://github.com/mattermost/mattermost/commit/a41db04d2746ab549d056db4ede4cd803f64989c
Security Fix Commit FIX COMMIT
https://github.com/mattermost/mattermost/commit/b822cea06bf5683a176e2c92711241bd29cd9389
Security Fix Commit FIX COMMIT
https://github.com/mattermost/mattermost/commit/e47349ea0fc072ee1dfb196d9bb1c8fd1a589224
Github.com/mattermost/mattermost server Source Repository REPOSITORY
https://github.com/mattermost/mattermost
Github.com/mattermost/mattermost server Security Information SECURITY
https://mattermost.com/security-updates

Frequently Asked Questions

What is CVE-2025-55073?
CVE-2025-55073 is a security vulnerability in Github.com/mattermost/mattermost server involving Mattermost allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL under CWE-306: Missing Authentication for Critical Function.
Which Github.com/mattermost/mattermost server versions are affected?
Affected versions include releases prior to 10.11.4, 10.5.12, 10.12.1, 8.0.0-20250929212932-a41db04d2746 across affected packages: github.com/mattermost/mattermost-server, github.com/mattermost/mattermost/server/v8.
What version fixes CVE-2025-55073?
Upgrading to 10.11.4, 10.5.12, 10.12.1, 8.0.0-20250929212932-a41db04d2746 (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, 10.12.1. Upgrade your dependency to 10.11.4, 10.5.12, 10.12.1 or later.
Is github.com/mattermost/mattermost/server/v8 affected?
Yes, github.com/mattermost/mattermost/server/v8 is affected in releases prior to 8.0.0-20250929212932-a41db04d2746. Upgrade your dependency to 8.0.0-20250929212932-a41db04d2746 or later.
What is the CVSS score of CVE-2025-55073?
CVE-2025-55073 has a CVSS v3.1 base score of 5.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L.
What CWE is associated with CVE-2025-55073?
CVE-2025-55073 is classified under CWE-306: Missing Authentication for Critical Function (The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.).
How can I check Go dependencies for CVE-2025-55073?
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
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-ff85-qw3h-g9vp",
  "modified" : "2025-11-17T17:58:31Z",
  "published" : "2025-11-14T09:30:27Z",
  "aliases" : [ "CVE-2025-55073" ],
  "summary" : "Mattermost allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL",
  "details" : "Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11, 10.12.x <= 10.12.0 fail to validate the relationship between the post being updated and the MSTeams plugin OAuth flow which allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L"
  } ],
  "affected" : [ {
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    },
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      "events" : [ {
        "introduced" : "10.11.0"
      }, {
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      } ]
    } ]
  }, {
    "package" : {
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      "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"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.12.0"
      }, {
        "fixed" : "10.12.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost/server/v8"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "8.0.0-20250929212932-a41db04d2746"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-55073"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/375ce229f4923205394d8f27925372b2cbf28130"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/6c288aa62bb3343183ec1d0a06360d14aa0193e9"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/a41db04d2746ab549d056db4ede4cd803f64989c"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/b822cea06bf5683a176e2c92711241bd29cd9389"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/e47349ea0fc072ee1dfb196d9bb1c8fd1a589224"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mattermost/mattermost"
  }, {
    "type" : "WEB",
    "url" : "https://mattermost.com/security-updates"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-306" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-11-17T17:58:31Z",
    "nvd_published_at" : "2025-11-14T08:15:45Z"
  }
}