{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "fixed": "4.0.5"
              },
              {
                "introduced": "4.1.0"
              },
              {
                "fixed": "4.1.1"
              },
              {
                "introduced": "0"
              },
              {
                "last_affected": "4.2.0-rc1"
              },
              {
                "introduced": "0"
              },
              {
                "last_affected": "4.2.0-rc2"
              },
              {
                "introduced": "0"
              },
              {
                "last_affected": "4.2.0-rc3"
              },
              {
                "introduced": "0"
              },
              {
                "last_affected": "4.2.0-rc4"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "ff513427371cd84e07b19c0586d419dbed976b31"
            },
            {
              "introduced": "0033e3e37b12cb5d951d21492500d66a6abc472b"
            },
            {
              "fixed": "5549c9149e80537d0f431b6b3ebf638c35568c4f"
            },
            {
              "introduced": "0"
            },
            {
              "last_affected": "f968c56890bd84295672ee0d46cc846cac2dbd47"
            },
            {
              "introduced": "0"
            },
            {
              "last_affected": "7018c187e13be731e4e8dc36b731b07128f030fa"
            },
            {
              "introduced": "0"
            },
            {
              "last_affected": "f4146835fe37856c0e109b819328772fa104ad80"
            },
            {
              "introduced": "0"
            },
            {
              "last_affected": "a5ce36d0882ae1b4b409a7b68233bf89591a5f95"
            }
          ],
          "repo": "https://github.com/mattermost/mattermost-server",
          "type": "GIT"
        }
      ]
    }
  ],
  "details": "An issue was discovered in Mattermost Server before 4.2.0, 4.1.1, and 4.0.5, when used as an OAuth 2.0 service provider. Sometimes. resource-owner authorization is bypassed, allowing account takeover.",
  "id": "CVE-2017-18894",
  "modified": "2026-03-13T21:48:38.333629728Z",
  "published": "2020-06-19T19:15:10.967Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://mattermost.com/security-updates/"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}