{"affected":[{"defaultStatus":"affected","ecosystem":"github","packageName":"libssh2/libssh2","product":"libssh2","source":"CNA: VulnCheck","vendor":"libssh2","versions":[{"lessThanOrEqual":"1.11.1","status":"affected","version":"0","versionType":"semver"},{"status":"unaffected","version":"a13bb6c773f0d55ad1628cede57e99803cd898d9","versionType":"git"}]},{"defaultStatus":"unknown","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)","source":"ADP: siemens-SADP","vendor":"Siemens","versions":[{"lessThan":"*","status":"affected","version":"V3.1.7","versionType":"custom"}]},{"defaultStatus":"unknown","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)","source":"ADP: siemens-SADP","vendor":"Siemens","versions":[{"lessThan":"*","status":"affected","version":"V3.1.7","versionType":"custom"}]},{"defaultStatus":"unknown","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)","source":"ADP: siemens-SADP","vendor":"Siemens","versions":[{"lessThan":"*","status":"affected","version":"V3.1.7","versionType":"custom"}]},{"defaultStatus":"unknown","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)","source":"ADP: siemens-SADP","vendor":"Siemens","versions":[{"lessThan":"*","status":"affected","version":"V3.1.7","versionType":"custom"}]},{"defaultStatus":"unknown","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)","source":"ADP: siemens-SADP","vendor":"Siemens","versions":[{"lessThan":"*","status":"affected","version":"V3.1.7","versionType":"custom"}]}],"cpeConfigurations":[{"negate":false,"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:libssh2:libssh2:*:*:*:*:*:*:*:*","versionEndIncluding":"1.11.1","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"OR"}],"cveId":"CVE-2026-66034","cwes":["CWE-125","CWE-908"],"description":"libssh2 through 1.11.1, fixed in commit a13bb6c, contains a missing bounds check vulnerability that allows a malicious SSH server to trigger an arbitrary-length heap out-of-bounds read and a free of an uninitialized pointer via the publickey subsystem. In libssh2_publickey_list_fetch(), the version 1 response parser reads a server-controlled comment_len value and advances the parse pointer without verifying sufficient bytes remain in the buffer, causing the out-of-bounds read to leak heap pointers from adjacent allocations defeating ASLR, followed by heap allocator state corruption when the error cleanup path frees an uninitialized pointer from a non-zeroed realloc() region.","epss":{"date":"2026-11-09","percentile":0.34767,"score":0.00402},"exploits":[],"kev":null,"metrics":[{"score":7.7,"severity":"high","source":"CNA: VulnCheck","vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","version":"4.0"},{"score":7.5,"severity":"high","source":"CNA: VulnCheck","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","version":"3.1"},{"score":7.7,"severity":"high","source":"NVD: disclosure@vulncheck.com","vector":"CVSS:4.0/AV:N/AC:H/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","version":"4.0"},{"score":7.5,"severity":"high","source":"NVD: disclosure@vulncheck.com","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","version":"3.1"}],"modifiedAt":1794314976462,"publishedAt":1784911338764,"references":[{"source":"CNA: VulnCheck","tags":["issue-tracking","patch"],"url":"https://github.com/libssh2/libssh2/pull/2202"},{"source":"CNA: VulnCheck","tags":["patch"],"url":"https://github.com/libssh2/libssh2/commit/a13bb6c773f0d55ad1628cede57e99803cd898d9"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/libssh2-heap-out-of-bounds-read-via-publickey-subsystem"},{"source":"ADP: siemens-SADP","tags":[],"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html"},{"source":"disclosure@vulncheck.com","tags":["Patch"],"url":"https://github.com/libssh2/libssh2/commit/a13bb6c773f0d55ad1628cede57e99803cd898d9"},{"source":"disclosure@vulncheck.com","tags":["Issue Tracking","Patch"],"url":"https://github.com/libssh2/libssh2/pull/2202"},{"source":"disclosure@vulncheck.com","tags":["Patch","Third Party Advisory"],"url":"https://www.vulncheck.com/advisories/libssh2-heap-out-of-bounds-read-via-publickey-subsystem"}],"remediation":[{"kind":"fix","source":"CNA: VulnCheck","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/libssh2/libssh2/pull/2202"},{"kind":"fix","source":"CNA: VulnCheck","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/libssh2/libssh2/commit/a13bb6c773f0d55ad1628cede57e99803cd898d9"},{"kind":"fix","source":"disclosure@vulncheck.com","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/libssh2/libssh2/commit/a13bb6c773f0d55ad1628cede57e99803cd898d9"},{"kind":"fix","source":"disclosure@vulncheck.com","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/libssh2/libssh2/pull/2202"},{"kind":"fix","source":"disclosure@vulncheck.com","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://www.vulncheck.com/advisories/libssh2-heap-out-of-bounds-read-via-publickey-subsystem"}],"revision":"f6f3a50440bf9feed354175fb3ec1dd7d130f5511a7e48a576b5a0c0a3d24df9","sources":[{"modifiedAt":1794314976462,"name":"CNA: VulnCheck","retrievedAt":1794316747536,"url":"https://www.cve.org/CVERecord?id=CVE-2026-66034"},{"modifiedAt":1794154200183,"name":"NVD","retrievedAt":1794161757056,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66034"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1794291558551,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-66034"}],"ssvc":{"assessedAt":1784851200000,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"total"},"status":"published","title":"libssh2 Heap Out-of-Bounds Read via publickey subsystem","updatedAt":1794316747536}