Security advisory

{
  "id": "7e032b6d28bf16728b6ac546fb84b6a9391fccf5a1811d962dd37d13767aa876",
  "url": "https://osv.dev/vulnerability/CVE-2021-37863",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-37863",
    "summary": "Mattermost 6.0 and earlier fails to sufficiently validate parameters during post creation, which allows authenticated attackers to cause a client-side crash of the web application via a maliciously crafted post.",
    "evidence": "osv:CVE-2021-37863",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2021-37863",
      "aliases": [
        "BIT-mattermost-2021-37863",
        "CVE-2021-37863"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/mattermost/mattermost",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "c9b959e58a660fbc928dd91b062d7bcbb5657017"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "6.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v6.0.0",
            "cloud-2021-08-12-1",
            "cloud-2021-07-29-1",
            "cloud-2021-07-15-1",
            "cloud-2021-07-01-1",
            "cloud-2021-06-16-1",
            "cloud-2021-06-02-1",
            "cloud-2021-05-21-1",
            "cloud-2021-05-05-1",
            "cloud-2021-04-22-1",
            "cloud-2021-03-23-1",
            "cloud-2021-03-12-1",
            "cloud-2021-02-25-1",
            "cloud-2021-02-24",
            "cloud-2021-02-10",
            "cloud-2021-01-26",
            "cloud-2021-01-12",
            "cloud-2020-12-18",
            "cloud-2020-12-08",
            "cloud-2020-11-24",
            "v5.2.0-rc2",
            "v5.2.0-rc1",
            "v5.1.0-rc1",
            "v5.0.0-rc1",
            "v4.10.0-rc1",
            "v4.9.0-rc1",
            "v4.8.0-rc1",
            "v4.7.0-rc1",
            "v4.6.0-rc2",
            "v4.6.0-rc1",
            "v4.5.0-rc1",
            "v4.4.0-rc1",
            "v4.3.0-rc1",
            "v4.2.0-rc1",
            "v0.5.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-37863.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:35.114455854Z",
      "provider": "osv",
      "references": [
        "https://mattermost.com/security-updates/",
        "https://hackerone.com/reports/1253732"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-37863",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 433675,
  "published_at": "2021-12-17T17:15:12.987+00:00"
}