CVE-2026-9957

import sys # This is a conceptual PoC generator for CVE-2026-9957 # It creates a malformed PDF structure intended to trigger the UAF. # Actual exploitation requires precise memory layout control. def generate_poc_pdf(filename): # Standard PDF Header pdf_header = b"%PDF-1.4\n" # Object 1: Catalog obj1 = b"1 0 obj\n<< /Type /Catalog /Pages 2 0 R >>\nendobj\n" # Object 2: Pages obj2 = b"2 0 obj\n<< /Type /Pages /Kids [3 0 R] /Count 1 >>\nendobj\n" # Object 3: Page # Contains a reference to a resource that might be trigger Use-After-Free # In a real scenario, specific JavaScript or font manipulation would be here. obj3 = b"3 0 obj\n<< /Type /Page /Parent 2 0 R /MediaBox [0 0 612 792] /Contents 4 0 R >>\nendobj\n" # Object 4: Content Stream (Placeholder for malicious stream) # This stream attempts to manipulate the PDF parser's internal state content_stream = b"BT /F1 12 Tf 100 700 Td (CVE-2026-9957 PoC) Tj ET" obj4 = f"4 0 obj\n<< /Length {len(content_stream)} >>\nstream\n{content_stream.decode()}\nendstream\nendobj\n".encode() # Object 5: Font obj5 = b"5 0 obj\n<< /Type /Font /Subtype /Type1 /BaseFont /Helvetica >>\nendobj\n" # Cross-reference table xref = b"xref\n0 6\n0000000000 65535 f \n0000000009 00000 n \n0000000058 00000 n \n0000000115 00000 n \n0000000224 00000 n \n0000000315 00000 n \n" # Trailer trailer = b"trailer\n<< /Size 6 /Root 1 0 R >>\nstartxref\n412\n%%EOF" with open(filename, "wb") as f: f.write(pdf_header) f.write(obj1) f.write(obj2) f.write(obj3) f.write(obj4) f.write(obj5) f.write(xref) f.write(trailer) print(f"[+] Generated PoC PDF file: {filename}") print("[!] Note: This file is a structural template. Triggering the specific UAF requires precise payload alignment.") if __name__ == "__main__": generate_poc_pdf("cve_2026_9957_poc.pdf")

{"cve": {"id": "CVE-2026-9957", "sourceIdentifier": "[email protected]", "published": "2026-05-28T23:16:53.900", "lastModified": "2026-05-29T12:16:29.550", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Use after free in PDF in Google Chrome prior to 148.0.7778.216 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted PDF file. (Chromium security severity: High)"}], "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:R/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-416"}]}], "references": [{"url": "https://chromereleases.googleblog.com/2026/05/stable-channel-update-for-desktop_0877304591.html", "source": "[email protected]"}, {"url": "https://issues.chromium.org/issues/504516117", "source": "[email protected]"}]}}