{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-27807", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-02-24T02:31:33.267Z", "datePublished": "2026-03-06T02:48:28.384Z", "dateUpdated": "2026-03-06T02:48:28.384Z"}, "containers": {"cna": {"title": "MarkUs: YAML alias (\u2018billion laughs\u2019) DoS in config upload", "problemTypes": [{"descriptions": [{"cweId": "CWE-776", "lang": "en", "description": "CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 4.9, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "HIGH", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/MarkUsProject/Markus/security/advisories/GHSA-m9rx-85mx-q9h6", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/MarkUsProject/Markus/security/advisories/GHSA-m9rx-85mx-q9h6"}, {"name": "https://github.com/MarkUsProject/Markus/releases/tag/v2.9.4", "tags": ["x_refsource_MISC"], "url": "https://github.com/MarkUsProject/Markus/releases/tag/v2.9.4"}], "affected": [{"vendor": "MarkUsProject", "product": "Markus", "versions": [{"version": "< 2.9.4", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-03-06T02:48:28.384Z"}, "descriptions": [{"lang": "en", "value": "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."}], "source": {"advisory": "GHSA-m9rx-85mx-q9h6", "discovery": "UNKNOWN"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "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", "lastModified": "2026-03-06T04:16:07.810", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 4.9, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "HIGH", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.2, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-03-06T04:16:07.810", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/MarkUsProject/Markus/releases/tag/v2.9.4"}, {"source": "security-advisories@github.com", "url": "https://github.com/MarkUsProject/Markus/security/advisories/GHSA-m9rx-85mx-q9h6"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-776"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}