USN-8051-2

USN-8051-1 fixed vulnerabilities in libssh. This update provides the corresponding updates for Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS.

Original advisory details:

It was discovered that libssh clients incorrectly handled the key exchange process. A remote attacker could possibly use this issue to cause libssh clients to crash, resulting in a denial of service. (CVE-2025-8277)

It was discovered that the libssh SCP client incorrectly sanitized paths received from servers. A remote attacker could use this issue to cause libssh SCP clients to overwrite files outside of the working directory and possibly execute arbitrary code. (CVE-2026-0964)

It was discovered that libssh incorrectly handled parsing configuration files. A local attacker could possibly use this issue to cause libssh to access non-regular files, resulting in a denial of service. (CVE-2026-0965)

It was discovered that libssh incorrectly handled the sshgethexa() function. A remote attacker could possibly use this issue to cause libssh to crash, resulting in a denial of service. (CVE-2026-0966)

It was discovered that libssh incorrectly handled certain regular expressions. A local attacker could possibly use this issue to cause libssh to consume resources, resulting in a denial of service. (CVE-2026-0967)

It was discovered that the libssh SFTP client incorrectly handled certain malformed longname fields. A remote attacker could use this issue to cause libssh SFTP clients to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-0968)

References

Affected packages

Ubuntu:Pro:16.04:LTS / libssh

Package

Name: libssh
Purl: pkg:deb/ubuntu/libssh@0.6.3-4.3ubuntu0.6+esm4?arch=source&distro=esm-infra/xenial

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

0.6.3-4.3ubuntu0.6+esm4

Affected versions

0.*

0.6.3-3ubuntu3

0.6.3-4.1

0.6.3-4.2

0.6.3-4.2ubuntu1

0.6.3-4.3

0.6.3-4.3ubuntu0.1

0.6.3-4.3ubuntu0.2

0.6.3-4.3ubuntu0.5

0.6.3-4.3ubuntu0.6

0.6.3-4.3ubuntu0.6+esm1

0.6.3-4.3ubuntu0.6+esm2

0.6.3-4.3ubuntu0.6+esm3

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libssh-4",
            "binary_version": "0.6.3-4.3ubuntu0.6+esm4"
        },
        {
            "binary_name": "libssh-dev",
            "binary_version": "0.6.3-4.3ubuntu0.6+esm4"
        },
        {
            "binary_name": "libssh-gcrypt-4",
            "binary_version": "0.6.3-4.3ubuntu0.6+esm4"
        },
        {
            "binary_name": "libssh-gcrypt-dev",
            "binary_version": "0.6.3-4.3ubuntu0.6+esm4"
        }
    ],
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}

Database specific

cves_map

{
    "cves": [
        {
            "severity": [
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2026-0964"
        },
        {
            "severity": [
                {
                    "score": "low",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2026-0965"
        },
        {
            "severity": [
                {
                    "score": "low",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2026-0966"
        },
        {
            "severity": [
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2026-0967"
        },
        {
            "severity": [
                {
                    "type": "Ubuntu",
                    "score": "medium"
                }
            ],
            "id": "CVE-2026-0968"
        }
    ],
    "ecosystem": "Ubuntu:Pro:16.04:LTS"
}

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8051-2.json"

Ubuntu:Pro:18.04:LTS / libssh

Package

Name: libssh
Purl: pkg:deb/ubuntu/libssh@0.8.0~20170825.94fa1e38-1ubuntu0.7+esm6?arch=source&distro=esm-infra/bionic

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

0.8.0~20170825.94fa1e38-1ubuntu0.7+esm6

Affected versions

0.*

0.7.5-1

0.8.0~20170825.94fa1e38-1

0.8.0~20170825.94fa1e38-1build1

0.8.0~20170825.94fa1e38-1ubuntu0.1

0.8.0~20170825.94fa1e38-1ubuntu0.2

0.8.0~20170825.94fa1e38-1ubuntu0.5

0.8.0~20170825.94fa1e38-1ubuntu0.6

0.8.0~20170825.94fa1e38-1ubuntu0.7

0.8.0~20170825.94fa1e38-1ubuntu0.7+esm3

0.8.0~20170825.94fa1e38-1ubuntu0.7+esm4

0.8.0~20170825.94fa1e38-1ubuntu0.7+esm5

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libssh-4",
            "binary_version": "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm6"
        },
        {
            "binary_name": "libssh-dev",
            "binary_version": "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm6"
        },
        {
            "binary_name": "libssh-gcrypt-4",
            "binary_version": "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm6"
        },
        {
            "binary_name": "libssh-gcrypt-dev",
            "binary_version": "0.8.0~20170825.94fa1e38-1ubuntu0.7+esm6"
        }
    ],
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8051-2.json"

cves_map

{
    "cves": [
        {
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "low",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2025-8277"
        },
        {
            "severity": [
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2026-0964"
        },
        {
            "severity": [
                {
                    "type": "Ubuntu",
                    "score": "low"
                }
            ],
            "id": "CVE-2026-0965"
        },
        {
            "severity": [
                {
                    "score": "low",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2026-0966"
        },
        {
            "severity": [
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2026-0967"
        },
        {
            "severity": [
                {
                    "type": "Ubuntu",
                    "score": "medium"
                }
            ],
            "id": "CVE-2026-0968"
        }
    ],
    "ecosystem": "Ubuntu:Pro:18.04:LTS"
}

Ubuntu:Pro:20.04:LTS / libssh

Package

Name: libssh
Purl: pkg:deb/ubuntu/libssh@0.9.3-2ubuntu2.5+esm3?arch=source&distro=esm-infra/focal

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

0.9.3-2ubuntu2.5+esm3

Affected versions

0.*

0.9.0-1ubuntu1

0.9.0-1ubuntu4

0.9.0-1ubuntu5

0.9.3-2ubuntu1

0.9.3-2ubuntu2

0.9.3-2ubuntu2.1

0.9.3-2ubuntu2.2

0.9.3-2ubuntu2.3

0.9.3-2ubuntu2.4

0.9.3-2ubuntu2.5

0.9.3-2ubuntu2.5+esm1

0.9.3-2ubuntu2.5+esm2

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libssh-4",
            "binary_version": "0.9.3-2ubuntu2.5+esm3"
        },
        {
            "binary_name": "libssh-dev",
            "binary_version": "0.9.3-2ubuntu2.5+esm3"
        },
        {
            "binary_name": "libssh-gcrypt-4",
            "binary_version": "0.9.3-2ubuntu2.5+esm3"
        },
        {
            "binary_name": "libssh-gcrypt-dev",
            "binary_version": "0.9.3-2ubuntu2.5+esm3"
        }
    ],
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8051-2.json"

cves_map

{
    "cves": [
        {
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "low",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2025-8277"
        },
        {
            "severity": [
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2026-0964"
        },
        {
            "severity": [
                {
                    "score": "low",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2026-0965"
        },
        {
            "severity": [
                {
                    "score": "low",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2026-0966"
        },
        {
            "severity": [
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2026-0967"
        },
        {
            "severity": [
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ],
            "id": "CVE-2026-0968"
        }
    ],
    "ecosystem": "Ubuntu:Pro:20.04:LTS"
}