It was discovered that libssh incorrectly performed bounds checking when processing SFTP extensions. If a client application queried extension data out of bounds, it could cause the application to crash, resulting in a denial of service, or exhibit unintended behavior.
{
"binaries": [
{
"binary_name": "libssh-4",
"binary_version": "0.9.6-2ubuntu0.22.04.7"
},
{
"binary_name": "libssh-gcrypt-4",
"binary_version": "0.9.6-2ubuntu0.22.04.7"
}
],
"availability": "No subscription required"
}{
"cves": [
{
"id": "CVE-2026-3731",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
},
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
]
}
],
"ecosystem": "Ubuntu:22.04:LTS"
}
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8093-1.json"
{
"binaries": [
{
"binary_name": "libssh-4",
"binary_version": "0.10.6-2ubuntu0.4"
},
{
"binary_name": "libssh-gcrypt-4",
"binary_version": "0.10.6-2ubuntu0.4"
}
],
"availability": "No subscription required"
}{
"cves": [
{
"id": "CVE-2026-3731",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
},
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
]
}
],
"ecosystem": "Ubuntu:24.04:LTS"
}
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8093-1.json"
{
"binaries": [
{
"binary_name": "libssh-4",
"binary_version": "0.11.2-1ubuntu0.3"
}
],
"availability": "No subscription required"
}{
"cves": [
{
"id": "CVE-2026-3731",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
},
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
]
}
],
"ecosystem": "Ubuntu:25.10"
}
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8093-1.json"
{
"binaries": [
{
"binary_name": "libssh-4",
"binary_version": "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7"
},
{
"binary_name": "libssh-gcrypt-4",
"binary_version": "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm7"
}
],
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}{
"cves": [
{
"id": "CVE-2026-3731",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
},
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
]
}
],
"ecosystem": "Ubuntu:Pro:18.04:LTS"
}
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8093-1.json"
{
"binaries": [
{
"binary_name": "libssh-4",
"binary_version": "0.9.3-2ubuntu2.5+esm4"
},
{
"binary_name": "libssh-gcrypt-4",
"binary_version": "0.9.3-2ubuntu2.5+esm4"
}
],
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}{
"cves": [
{
"id": "CVE-2026-3731",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
},
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
]
}
],
"ecosystem": "Ubuntu:Pro:20.04:LTS"
}
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8093-1.json"