{"attribution":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","cve":{"id":"CVE-2026-66032","sourceIdentifier":"disclosure@vulncheck.com","published":"2026-07-24T17:17:35.120","lastModified":"2026-11-10T13:19:37.883","vulnStatus":"Modified","cveTags":[],"descriptions":[{"lang":"en","value":"libssh2 through 1.11.1, fixed in commit 5e47761, contains a double-free vulnerability in the sftp_open() function in src/sftp.c that allows a malicious SSH server to corrupt the heap of any authenticated client opening an SFTP session. When a server responds to SSH_FXP_OPEN with SSH_FXP_STATUS containing FX_OK, the response data buffer is freed, and if a subsequent sftp_packet_require() call returns a specific error such as LIBSSH2_ERROR_CHANNEL_PACKET_EXCEEDED, the same pointer is freed a second time, enabling tcache dup conditions on glibc systems that allow overlapping allocations and function pointer overwrites."},{"lang":"es","value":"libssh2 hasta la versión 1.11.1, corregida en el commit 5e47761, contiene una vulnerabilidad de doble liberación de memoria en la función sftp_open() en src/sftp.c que permite a un servidor SSH malicioso corromper el heap de cualquier cliente autenticado que abre una sesión SFTP. Cuando un servidor responde a SSH_FXP_OPEN con SSH_FXP_STATUS que contiene FX_OK, el búfer de datos de respuesta es liberado, y si una llamada posterior a sftp_packet_require() devuelve un error específico como LIBSSH2_ERROR_CHANNEL_PACKET_EXCEEDED, el mismo puntero es liberado una segunda vez, lo que habilita condiciones de tcache dup en sistemas glibc que permiten asignaciones superpuestas y sobrescrituras de punteros de función."}],"affected":[{"source":"disclosure@vulncheck.com","affectedData":[{"vendor":"libssh2","product":"libssh2","defaultStatus":"affected","repo":"https://github.com/libssh2/libssh2","packageURL":"pkg:github/libssh2/libssh2","versions":[{"version":"0","lessThanOrEqual":"1.11.1","versionType":"semver","status":"affected"},{"version":"5e4776146552d898b9c0e1b313cd093fa8dc92d0","versionType":"git","status":"unaffected"}]}]},{"source":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","affectedData":[{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)","defaultStatus":"unknown","versions":[{"version":"V3.1.7","lessThan":"*","versionType":"custom","status":"affected"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)","defaultStatus":"unknown","versions":[{"version":"V3.1.7","lessThan":"*","versionType":"custom","status":"affected"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)","defaultStatus":"unknown","versions":[{"version":"V3.1.7","lessThan":"*","versionType":"custom","status":"affected"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)","defaultStatus":"unknown","versions":[{"version":"V3.1.7","lessThan":"*","versionType":"custom","status":"affected"}]},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)","defaultStatus":"unknown","versions":[{"version":"V3.1.7","lessThan":"*","versionType":"custom","status":"affected"}]}]}],"metrics":{"cvssMetricV40":[{"source":"disclosure@vulncheck.com","type":"Secondary","cvssData":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/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":8.7,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","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":"disclosure@vulncheck.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":2.8,"impactScore":5.9}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-07-24T00:00:00+00:00","id":"CVE-2026-66032","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"role":"CISA 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