CVE-2025-8277
Full vulnerability record from the local CVENow database.
Description
A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually exhaust system memory. This issue can lead to crashes on the client side, particularly when using libgcrypt, which impacts application stability and availability.
Severity
LOW
CVSS score
3.1
(v3.1)
Vulnerability status
Deferred
Source identifier
Published
2025-09-09 12:15:30.677000
Last modified
2026-10-18 21:10:00.120000
View original CVE JSON
{
"id": "CVE-2025-8277",
"sourceIdentifier": "[email protected]",
"published": "2025-09-09T12:15:30.677",
"lastModified": "2026-10-18T21:10:00.120",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually exhaust system memory. This issue can lead to crashes on the client side, particularly when using libgcrypt, which impacts application stability and availability."
},
{
"lang": "es",
"value": "Se encontró una falla en el manejo de libssh de los procesos de intercambio de claves (KEX) cuando un cliente envía repetidamente suposiciones KEX incorrectas. La biblioteca no libera memoria durante estas operaciones de renegociación de clave, lo que puede agotar gradualmente la memoria del sistema. Este problema puede provocar fallos en el lado del cliente, particularmente al usar libgcrypt, lo que afecta la estabilidad y disponibilidad de la aplicación."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"defaultStatus": "unaffected",
"collectionURL": "https://www.libssh.org",
"packageName": "libssh",
"versions": [
{
"version": "0.6.0",
"lessThan": "0.11.3",
"versionType": "semver",
"status": "affected"
}
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 9",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "libssh",
"cpes": [
"cpe:/a:redhat:enterprise_linux:9::appstream",
"cpe:/o:redhat:enterprise_linux:9::baseos"
],
"versions": [
{
"version": "0:0.10.4-18.el9",
"lessThan": "*",
"versionType": "rpm",
"status": "unaffected"
}
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 9",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "libssh",
"cpes": [
"cpe:/a:redhat:enterprise_linux:9::appstream",
"cpe:/o:redhat:enterprise_linux:9::baseos"
],
"versions": [
{
"version": "0:0.10.4-18.el9",
"lessThan": "*",
"versionType": "rpm",
"status": "unaffected"
}
]
},
{
"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"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 6",
"defaultStatus": "unknown",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "libssh2",
"cpes": [
"cpe:/o:redhat:enterprise_linux:6"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 7",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "libssh2",
"cpes": [
"cpe:/o:redhat:enterprise_linux:7"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 8",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "libssh",
"cpes": [
"cpe:/o:redhat:enterprise_linux:8"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat OpenShift Container Platform 4",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "openshift/ose-rhel-coreos-8",
"cpes": [
"cpe:/a:redhat:openshift:4"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat OpenShift Container Platform 4",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "openshift/ose-rhel-coreos-9",
"cpes": [
"cpe:/a:redhat:openshift:4"
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L",
"baseScore": 3.1,
"baseSeverity": "LOW",
"attackVector": "NETWORK",
"attackComplexity": "HIGH",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "LOW"
},
"exploitabilityScore": 1.6,
"impactScore": 1.4
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2025-09-09T19:28:17.013547Z",
"id": "CVE-2025-8277",
"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-401"
}
]
}
],
"references": [
{
"url": "https://access.redhat.com/errata/RHSA-2026:18683",
"source": "[email protected]"
},
{
"url": "https://access.redhat.com/security/cve/CVE-2025-8277",
"source": "[email protected]"
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2383888",
"source": "[email protected]"
},
{
"url": "https://www.libssh.org/security/advisories/CVE-2025-8277.txt",
"source": "[email protected]"
}
]
}