CVE-2025-14822: Github.com/mattermost/mattermost server Mattermost Is Vulnerable To CPU Vulnerability

LOW
Advisory Identifier: GHSA-9r42-rhw3-2222
CVSS 3.1
CWE-770 CWE-407
Published
Advisory Summary

CVE-2025-14822 is a LOW (CVSS 3.1) mattermost is vulnerable to cpu vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting Github.com/mattermost/mattermost server libraries in the Go ecosystem. The issue involves mattermost is vulnerable to cpu exhaustion via crafted http request. Remediation is available by upgrading affected packages to version 10.11.9, 11.2.0.

CVE-2025-14822 at a Glance

CVE Identifier CVE-2025-14822
GHSA Identifier GHSA-9r42-rhw3-2222
Severity LOW
CVSS v3.1 Base Score 3.1
CWE Classification CWE-770: Allocation of Resources Without Limits or Throttling
Affected Product Github.com/mattermost/mattermost server
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 3.1

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

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

How to Fix CVE-2025-14822

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: 10.11.9
Upgrade github.com/mattermost/mattermost-server to 10.11.9
github.com/mattermost/mattermost-server fixed: 11.2.0
Upgrade github.com/mattermost/mattermost-server to 11.2.0
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-2025-14822, 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 10.11.9), 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-770: Allocation of Resources Without Limits or Throttling, where the product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. 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 <= 10.11.8 fail to validate input size before processing hashtags which allows an authenticated attacker to exhaust CPU resources via a single HTTP request containing a post with thousands space-separated tokens.

CVE-2025-14822 Affected Github.com/mattermost/mattermost server Versions

2 component(s)
Fixed Versions:
10.11.911.2.0
Product / Package Ecosystem Affected Versions Fixed Version
github.com/mattermost/mattermost-server
Go
≥ 10.11.0
< 10.11.9
10.11.9
github.com/mattermost/mattermost-server
Go
≥ 11.0.0
< 11.2.0
11.2.0

References

Frequently Asked Questions

What is CVE-2025-14822?
CVE-2025-14822 is a security vulnerability in Github.com/mattermost/mattermost server involving Mattermost is vulnerable to CPU exhaustion via crafted HTTP request under CWE-770: Allocation of Resources Without Limits or Throttling.
Which Github.com/mattermost/mattermost server versions are affected?
Affected versions include releases prior to 10.11.9, 11.2.0 across affected packages: github.com/mattermost/mattermost-server.
What version fixes CVE-2025-14822?
Upgrading to 10.11.9, 11.2.0 (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 10.11.9, 11.2.0. Upgrade your dependency to 10.11.9, 11.2.0 or later.
What is the CVSS score of CVE-2025-14822?
CVE-2025-14822 has a CVSS v3.1 base score of 3.1 (LOW) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with CVE-2025-14822?
CVE-2025-14822 is classified under CWE-770: Allocation of Resources Without Limits or Throttling (The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.).
How can I check Go dependencies for CVE-2025-14822?
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-9r42-rhw3-2222",
  "modified" : "2026-02-27T22:05:20Z",
  "published" : "2026-01-16T09:31:21Z",
  "aliases" : [ "CVE-2025-14822" ],
  "summary" : "Mattermost is vulnerable to CPU exhaustion via crafted HTTP request",
  "details" : "Mattermost versions 10.11.x <= 10.11.8 fail to validate input size before processing hashtags which allows an authenticated attacker to exhaust CPU resources via a single HTTP request containing a post with thousands space-separated tokens.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.11.0"
      }, {
        "fixed" : "10.11.9"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.11.8"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0"
      }, {
        "fixed" : "11.2.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-14822"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/4d86263f5430d0eb991fc52ec886cf778cb072e6"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/b3d6c0c564c1a79e54e5105d0a8b60fc58a2bdee"
  }, {
    "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-2026-4325"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-407", "CWE-770" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-01-16T20:54:02Z",
    "nvd_published_at" : "2026-01-16T09:16:01Z"
  }
}