« Volver al listado

CVE-2026-91120

Estado: AplazadaMedia (5.4)—

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, provider-controlled video titles in lazy video embeds could be reparsed as HTML when Discourse generated notification emails or chat summaries. A user with standard posting privileges could create a post for an enabled YouTube, Vimeo, or TikTok provider whose title contained markup, and the email and chat-summary rendering path would place that markup into the output instead of treating it solely as text.

Leer descripción completaMostrar menos

Recipients using HTML-capable email clients could see injected content, potentially including event handlers, but the issue did not directly expose a Discourse browser session or affect the forum page itself. Lazy video embeds must be enabled, which is the default configuration. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.

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.

CWE-79 (XSS) en aplicación web Discourse con AV:N/PR:L permite inyectar markup en títulos de videos que se renderizan en emails y resúmenes de chat. Los clientes de email HTML pueden ejecutar handlers inyectados.

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

Restrict Web-Based ContentVulnerability ScanningUser TrainingUser Account ManagementPrivileged Account ManagementNetwork Segmentation

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Discourse — DiscourseAI

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-91120",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-91120",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-09-24T17:24:51.329319Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.4,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 2.5,
        "exploitabilityScore": 2.8
      }
    ]
  },
  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "discourse",
          "product": "discourse",
          "versions": [
            {
              "status": "affected",
              "version": "< 2026.8.0"
            },
            {
              "status": "affected",
              "version": ">= 2026.7.0-latest, < 2026.7.2"
            },
            {
              "status": "affected",
              "version": ">= 2026.6.0-latest, < 2026.6.3"
            },
            {
              "status": "affected",
              "version": ">= 2026.1.0-latest, < 2026.1.8"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-09-24T18:19:06.397",
  "references": [
    {
      "url": "https://github.com/discourse/discourse/commit/6bf1cdcb3ae1aa146e1fd953a62046bf4a1f143f",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/discourse/discourse/commit/8338919df4ecbd0fb85314b762772cc033b764e3",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/discourse/discourse/commit/e7de8285203a2edf85beff3b951e66aeb7e5dc76",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/discourse/discourse/commit/ed8b47df80bcc9f0bd70773fc399c9386f9d52dd",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/discourse/discourse/pull/42882",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/discourse/discourse/security/advisories/GHSA-h7cg-2vww-m45c",
      "source": "security-advisories@github.com"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, provider-controlled video titles in lazy video embeds could be reparsed as HTML when Discourse generated notification emails or chat summaries. A user with standard posting privileges could create a post for an enabled YouTube, Vimeo, or TikTok provider whose title contained markup, and the email and chat-summary rendering path would place that markup into the output instead of treating it solely as text. Recipients using HTML-capable email clients could see injected content, potentially including event handlers, but the issue did not directly expose a Discourse browser session or affect the forum page itself. Lazy video embeds must be enabled, which is the default configuration. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0."
    }
  ],
  "lastModified": "2026-09-24T18:19:06.540",
  "sourceIdentifier": "security-advisories@github.com"
}