User Manager can demote bot accounts to guest without bot-management permission

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-8823",
    "assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
    "assignerShortName": "Mattermost",
    "dateUpdated": "2026-06-22T16:12:31.350Z",
    "dateReserved": "2026-05-18T10:05:31.691Z",
    "datePublished": "2026-06-22T13:41:28.404Z",
    "state": "PUBLISHED"
  },
  "containers": {
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        "orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
        "shortName": "Mattermost",
        "dateUpdated": "2026-06-22T13:41:28.404Z"
      },
      "title": "User Manager can demote bot accounts to guest without bot-management permission",
      "descriptions": [
        {
          "lang": "en",
          "value": "Mattermost versions 11.7.x <= 11.7.0, 10.11.x <= 10.11.17 fail to validate bot targets when demoting users to guests which allows a lower-privileged administrator to degrade arbitrary bot accounts via the standard demote-user API.. Mattermost Advisory ID: MMSA-2026-00669"
        }
      ],
      "affected": [
        {
          "vendor": "Mattermost",
          "product": "Mattermost",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "11.7.0",
              "status": "affected",
              "versionType": "semver",
              "lessThanOrEqual": "11.7.0"
            },
            {
              "version": "10.11.0",
              "status": "affected",
              "versionType": "semver",
              "lessThanOrEqual": "10.11.17"
            },
            {
              "version": "11.8.0",
              "status": "unaffected"
            },
            {
              "version": "11.7.1",
              "status": "unaffected"
            },
            {
              "version": "10.11.18",
              "status": "unaffected"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "CWE-863: Incorrect Authorization",
              "cweId": "CWE-863",
              "type": "CWE"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://mattermost.com/security-updates",
          "name": "MMSA-2026-00669",
          "tags": [
            "vendor-advisory"
          ]
        }
      ],
      "metrics": [
        {
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
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          "cvssV3_1": {
            "version": "3.1",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L",
            "attackVector": "NETWORK",
            "attackComplexity": "LOW",
            "privilegesRequired": "HIGH",
            "userInteraction": "NONE",
            "scope": "UNCHANGED",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "availabilityImpact": "LOW",
            "baseScore": 3.8,
            "baseSeverity": "LOW"
          }
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Update Mattermost to versions 11.8.0, 11.7.1, 10.11.18 or higher."
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Edgar Bellot Micó",
          "type": "finder"
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      ]
    },
    "adp": [
      {
        "providerMetadata": {
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP",
          "dateUpdated": "2026-06-22T16:12:31.350Z"
        },
        "title": "CISA ADP Vulnrichment",
        "metrics": [
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}