FKIE_CVE-2026-2456

Vulnerability from fkie_nvd - Published: 2026-03-16 14:19 - Updated: 2026-03-18 18:27
Severity
5.3 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H
5.7 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H
Summary
Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 Mattermost fails to limit the size of responses from integration action endpoints, which allows an authenticated attacker to cause server memory exhaustion and denial of service via a malicious integration server that returns an arbitrarily large response when a user clicks an interactive message button.. Mattermost Advisory ID: MMSA-2026-00571
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 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "B6E5F368-358C-429B-8F04-3C8DF4A71A91",
              "versionEndExcluding": "10.11.11",
              "versionStartIncluding": "10.11.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "7F64C167-943D-4F3F-9374-BCC8DECB3881",
              "versionEndExcluding": "11.2.3",
              "versionStartIncluding": "11.2.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "945A6E29-209F-4992-8692-BEF63DCB6B98",
              "versionEndExcluding": "11.3.1",
              "versionStartIncluding": "11.3.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Mattermost versions 11.3.x \u003c= 11.3.0, 11.2.x \u003c= 11.2.2, 10.11.x \u003c= 10.11.10 Mattermost fails to limit the size of responses from integration action endpoints, which allows an authenticated attacker to cause server memory exhaustion and denial of service via a malicious integration server that returns an arbitrarily large response when a user clicks an interactive message button.. Mattermost Advisory ID: MMSA-2026-00571"
    },
    {
      "lang": "es",
      "value": "Versiones de Mattermost 11.3.x \u0026lt;= 11.3.0, 11.2.x \u0026lt;= 11.2.2, 10.11.x \u0026lt;= 10.11.10 Mattermost no limita el tama\u00f1o de las respuestas de los puntos finales de acci\u00f3n de integraci\u00f3n, lo que permite a un atacante autenticado causar el agotamiento de la memoria del servidor y denegaci\u00f3n de servicio a trav\u00e9s de un servidor de integraci\u00f3n malicioso que devuelve una respuesta arbitrariamente grande cuando un usuario hace clic en un bot\u00f3n de mensaje interactivo. ID de Aviso de Mattermost: MMSA-2026-00571"
    }
  ],
  "id": "CVE-2026-2456",
  "lastModified": "2026-03-18T18:27:57.000",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 3.6,
        "source": "responsibledisclosure@mattermost.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 5.7,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.1,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-03-16T14:19:29.190",
  "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-789"
        }
      ],
      "source": "responsibledisclosure@mattermost.com",
      "type": "Secondary"
    }
  ]
}


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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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