CVE-2026-55491

{
  "id": "CVE-2026-55491",
  "sourceIdentifier": "[email protected]",
  "published": "2026-08-20T22:17:22.347",
  "lastModified": "2026-10-26T10:10:00.140",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "BigBlueButton is an open-source virtual classroom. Prior to 3.0.29, BigBlueButton failed to escape meetingName in record-and-playback/screenshare/playback/index.html.erb when generating the screenshare playback format. A low-privileged user could store a crafted meeting name that embedded script content, and the script executed in another user's browser when that user replayed the recording. This issue is fixed in version 3.0.29."
    },
    {
      "lang": "es",
      "value": "BigBlueButton es un aula virtual de código abierto. Antes de la versión 3.0.29, BigBlueButton no logró escapar el nombre de la reunión en record-and-playback/screenshare/playback/index.html.erb al generar el formato de reproducción de la pantalla compartida. Un usuario de bajo privilegio podría almacenar un nombre de reunión manipulado que incrustaba contenido de script, y el script se ejecutaba en el navegador de otro usuario cuando ese usuario reproducía la grabación. Este problema está solucionado en la versión 3.0.29."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "bigbluebutton",
          "product": "bigbluebutton",
          "versions": [
            {
              "version": "< 3.0.29",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
          "baseScore": 5.4,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "REQUIRED",
          "scope": "CHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.3,
        "impactScore": 2.7
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-08-21T15:49:35.408716Z",
          "id": "CVE-2026-55491",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/bigbluebutton/bigbluebutton/commit/a53f2b92022388bfa4109d3136d1f3a932404b1b",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.29",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-57p5-c888-74f9",
      "source": "[email protected]"
    }
  ]
}