FKIE_CVE-2026-3637

Vulnerability from fkie_nvd - Published: 2026-05-18 08:16 - Updated: 2026-10-14 20:10
Severity
4.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Summary
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and patch endpoints.. Mattermost Advisory ID: MMSA-2026-00627
References
responsibledisclosure@mattermost.comhttps://mattermost.com/security-updatesVendor Advisory
Impacted products
Vendor Product Version
mattermost mattermost_server *
mattermost mattermost_server *
mattermost mattermost_server *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Mattermost",
          "vendor": "Mattermost",
          "versions": [
            {
              "lessThanOrEqual": "11.5.1",
              "status": "affected",
              "version": "11.5.0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "10.11.13",
              "status": "affected",
              "version": "10.11.0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "11.4.3",
              "status": "affected",
              "version": "11.4.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "11.6.0"
            },
            {
              "status": "unaffected",
              "version": "11.5.2"
            },
            {
              "status": "unaffected",
              "version": "10.11.14"
            },
            {
              "status": "unaffected",
              "version": "11.4.4"
            }
          ]
        }
      ],
      "source": "responsibledisclosure@mattermost.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "413D9405-79C3-4299-B0DC-40D9EE5CC717",
              "versionEndExcluding": "10.11.14",
              "versionStartIncluding": "10.11.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "CF171039-837A-4D23-87EB-F328AD04976C",
              "versionEndExcluding": "11.4.4",
              "versionStartIncluding": "11.4.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "726AD6AD-6C01-45BB-9115-B8209717A6D4",
              "versionEndExcluding": "11.5.2",
              "versionStartIncluding": "11.5.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Mattermost versions 11.5.x \u003c= 11.5.1, 10.11.x \u003c= 10.11.13, 11.4.x \u003c= 11.4.3 fail to check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and patch endpoints.. Mattermost Advisory ID: MMSA-2026-00627"
    },
    {
      "lang": "es",
      "value": "Mattermost versiones 11.5.x menor o igual que 11.5.1, 10.11.x menor o igual que 10.11.13, 11.4.x menor o igual que 11.4.3 no verifican el permiso de canal create_post durante las operaciones de edici\u00f3n de publicaciones, lo que permite a un atacante autenticado con privilegios de publicaci\u00f3n revocados modificar sus publicaciones existentes a trav\u00e9s de solicitudes directas a la API a los puntos finales de actualizaci\u00f3n y parche de publicaciones. ID de Aviso de Mattermost: MMSA-2026-00627"
    }
  ],
  "id": "CVE-2026-3637",
  "lastModified": "2026-10-14T20:10:00.190",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 4.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 1.4,
        "source": "responsibledisclosure@mattermost.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-3637",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-05-18T14:34:50.396017Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-05-18T08:16:14.040",
  "references": [
    {
      "source": "responsibledisclosure@mattermost.com",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://mattermost.com/security-updates"
    }
  ],
  "sourceIdentifier": "responsibledisclosure@mattermost.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-862"
        }
      ],
      "source": "responsibledisclosure@mattermost.com",
      "type": "Secondary"
    }
  ]
}



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