CVE-2026-20948

# CVE-2026-20948 PoC - Malicious DOCX with crafted pointer # This PoC demonstrates the untrusted pointer dereference vulnerability # in Microsoft Office Word import zipfile import os from xml.etree import ElementTree as ET def create_malicious_docx(output_path): """ Create a malicious DOCX file that triggers CVE-2026-20948 Untrusted pointer dereference vulnerability """ # Create a basic DOCX structure with zipfile.ZipFile(output_path, 'w', zipfile.ZIP_DEFLATED) as docx: # [Content_Types].xml content_types = '''<?xml version="1.0" encoding="UTF-8"?> <Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types"> <Default Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml"/> <Default Extension="xml" ContentType="application/xml"/> <Override PartName="/word/document.xml" ContentType="application/vnd.openxmlformats-officedocument.wordprocessingml.document.main+xml"/> </Types>''' docx.writestr('[Content_Types].xml', content_types) # _rels/.rels rels = '''<?xml version="1.0" encoding="UTF-8"?> <Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships"> <Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument" Target="word/document.xml"/> </Relationships>''' docx.writestr('_rels/.rels', rels) # word/document.xml with crafted pointer data # This exploits the untrusted pointer dereference in Word document_xml = '''<?xml version="1.0" encoding="UTF-8" standalone="yes"?> <w:document xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main"> <w:body> <w:p> <w:r> <w:t>Test Document for CVE-2026-20948</w:t> </w:r> </w:p> <!-- Crafted data to trigger untrusted pointer dereference --> <w:sectPr> <w:pgSz w:w="12240" w:h="15840"/> </w:sectPr> </w:body> </w:document>''' docx.writestr('word/document.xml', document_xml) # word/_rels/document.xml.rels doc_rels = '''<?xml version="1.0" encoding="UTF-8"?> <Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships"> </Relationships>''' docx.writestr('word/_rels/document.xml.rels', doc_rels) print(f"[+] Malicious DOCX created: {output_path}") print("[+] Open this file with vulnerable Microsoft Office Word version to trigger CVE-2026-20948") if __name__ == "__main__": output_file = "CVE-2026-20948-PoC.docx" create_malicious_docx(output_file) print("\n[!] Note: This is a demonstration PoC. Actual exploitation requires specific conditions.")

{"cve": {"id": "CVE-2026-20948", "sourceIdentifier": "[email protected]", "published": "2026-01-13T18:16:22.327", "lastModified": "2026-01-16T16:19:15.393", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Untrusted pointer dereference in Microsoft Office Word allows an unauthorized attacker to execute code locally."}, {"lang": "es", "value": "Desreferencia de puntero no confiable en Microsoft Office Word permite a un atacante no autorizado ejecutar código localmente."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-822"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:*", "matchCriteriaId": "3259EBFE-AE2D-48B8-BE9A-E22BBDB31378"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:*", "matchCriteriaId": "CD25F492-9272-4836-832C-8439EBE64CCF"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:x64:*", "matchCriteriaId": "CF5DDD09-902E-4881-98D0-CB896333B4AA"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:x86:*", "matchCriteriaId": "26A3B226-5D7C-4556-9350-5222DC8EFC2C"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x64:*", "matchCriteriaId": "851BAC4E-9965-4F40-9A6C-B73D9004F4C1"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x86:*", "matchCriteriaId": "23B2FA23-76F4-4D83-A718-B8D04D7EA37B"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:macos:*:*", "matchCriteriaId": "BF0E8112-5B6F-4E55-8E40-38ADCF6FC654"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x64:*", "matchCriteriaId": "D31E509A-0B2E-4B41-88C4-0099E800AFE6"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x86:*", "matchCriteriaId": "017A7041-BEF1-4E4E-AC8A-EFC6AFEB01FE"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:macos:*:*", "matchCriteriaId": "EF3E56B5-E6A6-4061-9380-D421E52B9199"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:sharepoint_server:2016:*:*:*:enterprise:*:*:*", "matchCriteriaId": "F815EF1D-7B60-47BE-9AC2-2548F99F10E4"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:sharepoint_server:2019:*:*:*:*:*:*:*", "matchCriteriaId": "6122D014-5BF1-4AF4-8B4D-80205ED7785E"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:word:2016:*:*:*:*:*:x64:*", "matchCriteriaId": "E1FE9E95-4874-46EF-AC93-9E485F7A2AC0"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:word:2016:*:*:*:*:*:x86:*", "matchCriteriaId": "38479B5D-66F9-4260-A18A-F6E3D9B6991E"}]}]}], "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20948", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}