TS3 Manager: Reflected XSS via /api/download port parameter steals operator session

{
  "id": "8d926a5680052e33ebac190f6196f23c21a7c12fb1e13c8b817d274bd66cf3c1",
  "url": "https://osv.dev/vulnerability/CVE-2026-54253",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "TS3 Manager: Reflected XSS via /api/download port parameter steals operator session",
    "summary": "TS3 Manager is modern web interface for maintaining Teamspeak3 servers. Prior to 2.2.6, the /api/download handler in packages/server/routes/api.js passes the attacker-controlled port query parameter to socket.connect(port, host) and returns the resulting error.message through res.status(400).send(error.message) as text/html without a Content Security Policy. When a logged-in operator follows a crafted top-level link, the reflected value executes in the manager origin. The token cookie set in packages/ui/src/store/modules/query.js lacks HttpOnly, Secure, and an explicit SameSite attribute, allowing the script to read the token and call the autofillform event in packages/server/socket.js. autofillform returns the decoded JWT, including the cleartext ServerQuery password, enabling operator-session hijacking and control of the managed TeamSpeak server when the operator uses administrative ServerQuery credentials. A valid operator session and user interaction are required. This issue is fixed in 2.2.6.",
    "evidence": "osv:CVE-2026-54253",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-54253",
      "aliases": [
        "CVE-2026-54253",
        "GHSA-3cgm-7p4g-gffj"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/joni1802/ts3-manager",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "961f5bdbaf8fe8caa320f3033623b5ad5317ed2e"
                },
                {
                  "fixed": "48df540786d2784c5d7b9bd55786d63e31288d07"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.2.6"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "48df540786d2784c5d7b9bd55786d63e31288d07"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "961f5bdbaf8fe8caa320f3033623b5ad5317ed2e"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v2.2.6"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.2.5",
            "v2.2.4-rc3",
            "v2.2.4-rc2",
            "v2.2.4-rc1",
            "v2.2.4",
            "v2.2.3",
            "v2.2.2",
            "v2.2.1",
            "v2.2.0",
            "v2.1.0",
            "v2.0.1",
            "v2.0.0",
            "v1.7.3",
            "v1.7.1",
            "v1.7.0",
            "v1.6.1",
            "v1.6.0",
            "v1.5.1",
            "v1.5.0",
            "v1.4.0",
            "v1.3.1",
            "v1.1.1-beta",
            "v1.0.0-alpha"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54253.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:37.957672275Z",
      "provider": "osv",
      "references": [
        "https://github.com/joni1802/ts3-manager/releases/tag/v2.2.6",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54253.json",
        "https://github.com/joni1802/ts3-manager/security/advisories/GHSA-3cgm-7p4g-gffj",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-54253",
        "https://github.com/joni1802/ts3-manager/commit/48df540786d2784c5d7b9bd55786d63e31288d07"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-79"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54253.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-54253",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 505254,
  "published_at": "2026-09-17T18:37:38.022+00:00"
}