{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "3.0.29"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "a53f2b92022388bfa4109d3136d1f3a932404b1b"
            },
            {
              "fixed": "e9d0534de2f014d1903d8c54885ca6acd5758a69"
            }
          ],
          "repo": "https://github.com/bigbluebutton/bigbluebutton",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-57p5-c888-74f9"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55491.json"
  },
  "details": "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.",
  "id": "CVE-2026-55491",
  "modified": "2026-08-23T03:42:20.237200247Z",
  "published": "2026-08-20T21:35:42.546Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.29"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55491.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-57p5-c888-74f9"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55491"
    },
    {
      "type": "FIX",
      "url": "https://github.com/bigbluebutton/bigbluebutton/commit/a53f2b92022388bfa4109d3136d1f3a932404b1b"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "BigBlueButton: Stored XSS in Screenshare Recording Playback via Unescaped Meeting Name"
}