{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "5.9.4"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4d47d5cdcf5d92c2c5bbbc19feada422923332e3"
            },
            {
              "fixed": "3bf77d5883be99c85ec153064307ce8ba25020f5"
            }
          ],
          "repo": "https://github.com/yamcs/yamcs",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-rxpg-wjf8-qv9c"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55549.json"
  },
  "details": "Yamcs is a mission control framework. Prior to 5.9.4, Yamcs reflects an attacker-controlled redirect_uri parameter from GET /auth/authorize into yamcs-core/src/main/resources/auth/templates/authorize.html without adequate HTML escaping by yamcs-core/src/main/java/org/yamcs/http/auth/AuthHandler.java and yamcs-core/src/main/java/org/yamcs/http/HandlerContext.java. A crafted authorization URL can execute JavaScript when opened by a Yamcs user. The script can access browser-held authentication material and transmit it to an attacker, enabling account compromise. This issue is fixed in version 5.9.4.",
  "id": "CVE-2026-55549",
  "modified": "2026-09-10T03:30:41.246172878Z",
  "published": "2026-08-28T17:15:52.840Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/yamcs/yamcs/releases/tag/yamcs-5.9.4"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55549.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/yamcs/yamcs/security/advisories/GHSA-rxpg-wjf8-qv9c"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55549"
    },
    {
      "type": "FIX",
      "url": "https://github.com/yamcs/yamcs/commit/4d47d5cdcf5d92c2c5bbbc19feada422923332e3"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Yamcs: Reflected XSS in the URL of the Authorize Endpoint"
}