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CVE-2026-20719

Estado: AnalizadaAlta (7.5)—

Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to prevent rendering of external SVGs on link embeds which allows unauthenticated users to crash the Mattermost webapp and desktop app via creating an issue or PR on GitHub.. Mattermost Advisory ID: MMSA-2026-00595

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

AV:N, PR:N, UI:N indica explotación remota sin autenticación (T1190). Availabilidad afectada (A:H) mediante crash de webapp/desktop por SVGs malformados = DoS por aplicación (T1499.004).

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Filter Network TrafficVulnerability ScanningPrivileged Account ManagementNetwork SegmentationLimit Access to Resource Over NetworkApplication Isolation and Sandboxing

Tecnologías afectadas (1)

Mattermost — Mattermost Server

CWE

Referencias

JSON original (NVD)

Mostrar
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          "role": "CISA Coordinator",
          "options": [
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              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
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              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-03-26T17:11:15.846505Z"
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          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
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  "published": "2026-03-25T17:16:30.307",
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      "tags": [
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      "source": "responsibledisclosure@mattermost.com",
      "description": [
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          "value": "CWE-754"
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      "value": "Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to prevent rendering of external SVGs on link embeds which allows unauthenticated users to crash the Mattermost webapp and desktop app via creating an issue or PR on GitHub.. Mattermost Advisory ID: MMSA-2026-00595"
    },
    {
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      "value": "Las versiones de Mattermost 11.4.x &lt;= 11.4.0, 11.3.x &lt;= 11.3.1, 11.2.x &lt;= 11.2.3, 10.11.x &lt;= 10.11.11 no impiden la renderización de SVG externos en incrustaciones de enlaces, lo que permite a usuarios no autenticados bloquear la aplicación web y la aplicación de escritorio de Mattermost mediante la creación de una incidencia o una PR en GitHub. ID de aviso de Mattermost: MMSA-2026-00595"
    }
  ],
  "lastModified": "2026-06-17T10:17:44.417",
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