{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2aa90f8a047c2484147de12c464d08d4be964029"
            }
          ],
          "repo": "https://github.com/markusproject/markus",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-m9rx-85mx-q9h6"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-776"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27807.json"
  },
  "details": "MarkUs is a web application for the submission and grading of student assignments. Prior to version 2.9.4, MarkUs allows course instructors to upload YAML files to create/update various entities (e.g., assignment settings). These YAML files are parsed with aliases enabled. This issue has been patched in version 2.9.4.",
  "id": "CVE-2026-27807",
  "modified": "2026-04-01T23:08:43.398857164Z",
  "published": "2026-03-06T02:48:28.384Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/MarkUsProject/Markus/releases/tag/v2.9.4"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27807.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/MarkUsProject/Markus/security/advisories/GHSA-m9rx-85mx-q9h6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27807"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "MarkUs: YAML alias (‘billion laughs’) DoS in config upload"
}