GHSA-RMVV-8V8W-RF7X

Vulnerability from github – Published: 2026-05-26 13:30 – Updated: 2026-06-29 19:21
VLAI
Summary
Mattermost doesn't validate user-supplied input in API request handlers
Details

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate user-supplied input in API request handlers which allows an authenticated attacker to crash the plugin process via a crafted HTTP request to the PR details endpoint. Mattermost Advisory ID: MMSA-2026-00638

Severity
4.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "11.6.0"
            },
            {
              "fixed": "11.6.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "11.6.0"
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "11.5.0"
            },
            {
              "fixed": "11.5.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "11.4.0"
            },
            {
              "fixed": "11.4.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "10.11.0"
            },
            {
              "fixed": "10.11.15"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/mattermost/mattermost-plugin-github"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.0.1-0.20260330164815-c2840e980b3c"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-4646"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1287"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-29T19:21:37Z",
    "nvd_published_at": "2026-05-22T11:16:22Z",
    "severity": "MODERATE"
  },
  "details": "Mattermost versions 11.6.x \u003c= 11.6.0, 11.5.x \u003c= 11.5.3, 11.4.x \u003c= 11.4.4, 10.11.x \u003c= 10.11.14 fail to validate user-supplied input in API request handlers which allows an authenticated attacker to crash the plugin process via a crafted HTTP request to the PR details endpoint. Mattermost Advisory ID: MMSA-2026-00638",
  "id": "GHSA-rmvv-8v8w-rf7x",
  "modified": "2026-06-29T19:21:37Z",
  "published": "2026-05-26T13:30:15Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4646"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mattermost/mattermost-plugin-github/commit/c2840e980b3c2bd08db656eaa6a0fe26bcbf4695"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/mattermost/mattermost"
    },
    {
      "type": "WEB",
      "url": "https://mattermost.com/security-updates"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Mattermost doesn\u0027t validate user-supplied input in API request handlers"
}



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