CVE-2026-59842
Full vulnerability record from the local CVENow database.
Description
A flaw was found in libssh. During server-side GSSAPI key exchange, a client-supplied Curve25519 public key shorter than the expected length is copied without proper length validation, leading to an out-of-bounds heap read. This could allow a remote unauthenticated attacker to disclose small amounts of server memory.
Severity
MEDIUM
CVSS score
5.3
(v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-07-21 12:18:57.727000
Last modified
2026-11-06 20:17:23.427000
View original CVE JSON
{
"id": "CVE-2026-59842",
"sourceIdentifier": "[email protected]",
"published": "2026-07-21T12:18:57.727",
"lastModified": "2026-11-06T20:17:23.427",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in libssh. During server-side GSSAPI key exchange, a client-supplied Curve25519 public key shorter than the expected length is copied without proper length validation, leading to an out-of-bounds heap read. This could allow a remote unauthenticated attacker to disclose small amounts of server memory."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 10",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "libssh",
"cpes": [
"cpe:/o:redhat:enterprise_linux:10.2"
],
"versions": [
{
"version": "0:0.12.0-3.el10_2",
"lessThan": "*",
"versionType": "rpm",
"status": "unaffected"
}
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Hardened Images",
"defaultStatus": "affected",
"collectionURL": "https://catalog.redhat.com/software/containers/",
"packageName": "libssh-main",
"cpes": [
"cpe:/a:redhat:hummingbird:1"
],
"versions": [
{
"version": "0.12.1-4.hum1",
"lessThan": "*",
"versionType": "rpm",
"status": "unaffected"
}
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 8",
"defaultStatus": "unaffected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "libssh",
"cpes": [
"cpe:/a:redhat:enterprise_linux:8"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 9",
"defaultStatus": "unaffected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "libssh",
"cpes": [
"cpe:/a:redhat:enterprise_linux:9"
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
"baseScore": 3.7,
"baseSeverity": "LOW",
"attackVector": "NETWORK",
"attackComplexity": "HIGH",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"availabilityImpact": "NONE"
},
"exploitabilityScore": 2.2,
"impactScore": 1.4
},
{
"source": "[email protected]",
"type": "Primary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"availabilityImpact": "NONE"
},
"exploitabilityScore": 3.9,
"impactScore": 1.4
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-07-22T14:00:56.434429Z",
"id": "CVE-2026-59842",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-125"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:a:libssh:libssh:0.12.0:*:*:*:*:*:*:*",
"matchCriteriaId": "C250851D-1948-4012-ABE4-FEBB369E3231"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:*",
"matchCriteriaId": "87DEB507-5B64-47D7-9A50-3B87FD1E571F"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*",
"matchCriteriaId": "D65C2163-CFC2-4ABB-8F4E-CB09CEBD006C"
}
]
}
]
},
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:arm64:*",
"matchCriteriaId": "63D81CCC-AECF-436A-B019-B3149585F92C"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:x64:*",
"matchCriteriaId": "472208E5-9850-47CD-8C7D-E1EBF7FDB2C7"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux:10.2:*:*:*:*:*:arm64:*",
"matchCriteriaId": "4DBA7603-2980-42BE-981C-FAE97568B00B"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux:10.2:*:*:*:*:*:x64:*",
"matchCriteriaId": "D28BC9F4-ECC6-411B-B445-B247FACD9530"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux_for_els:10.2:*:*:*:*:*:arm64:*",
"matchCriteriaId": "C78AA720-6EBB-4CA7-8831-22A7CBFE7A1C"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux_for_els:10.2:*:*:*:*:*:x64:*",
"matchCriteriaId": "1D055CB8-FA3A-4DB8-AB58-9B17F7EC552B"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux_for_eus:10.2:*:*:*:*:*:arm64:*",
"matchCriteriaId": "ADFDF403-9B07-48CF-8BB2-11054879BCF8"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux_for_eus:10.2:*:*:*:*:*:x64:*",
"matchCriteriaId": "E7AB6D4F-D513-45F8-BC00-5F6C93D0002D"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:10.0:*:*:*:*:*:*:*",
"matchCriteriaId": "31F91BA6-64D9-4248-8773-6B5B99CA01A0"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:10.2:*:*:*:*:*:*:*",
"matchCriteriaId": "157996FE-FC8B-4D4E-9538-E14BC0D8466F"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_els:10.2:*:*:*:*:*:*:*",
"matchCriteriaId": "1B8AC302-55C1-44FB-B66C-C6D0D6F5DBFE"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:10.2:*:*:*:*:*:*:*",
"matchCriteriaId": "F7F02954-7CB7-46F9-BBF1-3FAD6736F712"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:10.0:*:*:*:*:*:*:*",
"matchCriteriaId": "06A3271F-112F-4FB7-A2F7-6401A365FCBA"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:10.2:*:*:*:*:*:*:*",
"matchCriteriaId": "D6F30042-532F-4A7C-897B-1084C0587957"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_els:10.2:*:*:*:*:*:*:*",
"matchCriteriaId": "9BB0DAF9-794A-4DAF-A4C6-3DDD8E42F48D"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:10.2:*:*:*:*:*:*:*",
"matchCriteriaId": "DDDCBC52-F003-4776-8D21-B525CF8D8B8D"
}
]
}
]
}
],
"references": [
{
"url": "https://access.redhat.com/errata/RHSA-2026:42922",
"source": "[email protected]",
"tags": [
"Issue Tracking"
]
},
{
"url": "https://access.redhat.com/errata/RHSA-2026:55855",
"source": "[email protected]",
"tags": [
"Vendor Advisory"
]
},
{
"url": "https://access.redhat.com/security/cve/CVE-2026-59842",
"source": "[email protected]",
"tags": [
"Vendor Advisory"
]
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2498168",
"source": "[email protected]",
"tags": [
"Issue Tracking",
"Vendor Advisory"
]
}
]
}