CVE-2026-55491

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{"affected": [{"affectedData": [{"product": "bigbluebutton", "vendor": "bigbluebutton", "versions": [{"status": "affected", "version": "< 3.0.29"}]}], "source": "security-advisories@github.com"}], "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 c\u00f3digo abierto. Antes de la versi\u00f3n 3.0.29, BigBlueButton no logr\u00f3 escapar el nombre de la reuni\u00f3n en record-and-playback/screenshare/playback/index.html.erb al generar el formato de reproducci\u00f3n de la pantalla compartida. Un usuario de bajo privilegio podr\u00eda almacenar un nombre de reuni\u00f3n manipulado que incrustaba contenido de script, y el script se ejecutaba en el navegador de otro usuario cuando ese usuario reproduc\u00eda la grabaci\u00f3n. Este problema est\u00e1 solucionado en la versi\u00f3n 3.0.29."}], "id": "CVE-2026-55491", "lastModified": "2026-10-26T10:10:00.140", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 5.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.3, "impactScore": 2.7, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55491", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-21T15:49:35.408716Z", "version": "2.0.3"}}]}, "published": "2026-08-20T22:17:22.347", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/bigbluebutton/bigbluebutton/commit/a53f2b92022388bfa4109d3136d1f3a932404b1b"}, {"source": "security-advisories@github.com", "url": "https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.29"}, {"source": "security-advisories@github.com", "url": "https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-57p5-c888-74f9"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,3.0.29)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "bigbluebutton", "source": "cna", "vendor": "bigbluebutton"}, "product": "bigbluebutton", "vendor": "bigbluebutton"}], "created": "2026-08-20T22:45:02.856614+00:00", "updated": "2026-08-21T01:00:04.533551+00:00", "vendors": ["bigbluebutton", "bigbluebutton$PRODUCT$bigbluebutton"]}