USN-8023-1

It was discovered that Expat, contained within the xmltok library, incorrectly handled the initialization of parsers for external entities. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-24515)

It was discovered that Expat, contained within the xmltok library, incorrectly handled integer calculations when allocating memory for XML tags. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2026-25210)

References

Affected packages

Ubuntu:Pro:16.04:LTS / libxmltok

Package

Name: libxmltok
Purl: pkg:deb/ubuntu/libxmltok@1.2-3ubuntu0.16.04.1~esm5?arch=source&distro=esm-apps/xenial

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

1.2-3ubuntu0.16.04.1~esm5

Affected versions

1.*

1.2-3build3

1.2-3ubuntu0.16.04.1~esm1

1.2-3ubuntu0.16.04.1~esm2

1.2-3ubuntu0.16.04.1~esm3

1.2-3ubuntu0.16.04.1~esm4

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libxmltok1",
            "binary_version": "1.2-3ubuntu0.16.04.1~esm5"
        },
        {
            "binary_name": "libxmltok1-dev",
            "binary_version": "1.2-3ubuntu0.16.04.1~esm5"
        }
    ],
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8023-1.json"

cves_map

{
    "ecosystem": "Ubuntu:Pro:16.04:LTS",
    "cves": [
        {
            "id": "CVE-2026-24515",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-25210",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ]
}

Ubuntu:Pro:18.04:LTS / libxmltok

Package

Name: libxmltok
Purl: pkg:deb/ubuntu/libxmltok@1.2-4ubuntu0.18.04.1~esm6?arch=source&distro=esm-apps/bionic

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

1.2-4ubuntu0.18.04.1~esm6

Affected versions

1.*

1.2-4

1.2-4ubuntu0.18.04.1~esm1

1.2-4ubuntu0.18.04.1~esm2

1.2-4ubuntu0.18.04.1~esm3

1.2-4ubuntu0.18.04.1~esm4

1.2-4ubuntu0.18.04.1~esm5

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libxmltok1",
            "binary_version": "1.2-4ubuntu0.18.04.1~esm6"
        },
        {
            "binary_name": "libxmltok1-dev",
            "binary_version": "1.2-4ubuntu0.18.04.1~esm6"
        }
    ],
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8023-1.json"

cves_map

{
    "ecosystem": "Ubuntu:Pro:18.04:LTS",
    "cves": [
        {
            "id": "CVE-2026-24515",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-25210",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ]
}

Ubuntu:Pro:20.04:LTS / libxmltok

Package

Name: libxmltok
Purl: pkg:deb/ubuntu/libxmltok@1.2-4ubuntu0.20.04.1~esm6?arch=source&distro=esm-apps/focal

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

1.2-4ubuntu0.20.04.1~esm6

Affected versions

1.*

1.2-4

1.2-4ubuntu0.20.04.1~esm1

1.2-4ubuntu0.20.04.1~esm2

1.2-4ubuntu0.20.04.1~esm3

1.2-4ubuntu0.20.04.1~esm4

1.2-4ubuntu0.20.04.1~esm5

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libxmltok1",
            "binary_version": "1.2-4ubuntu0.20.04.1~esm6"
        },
        {
            "binary_name": "libxmltok1-dev",
            "binary_version": "1.2-4ubuntu0.20.04.1~esm6"
        }
    ],
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8023-1.json"

cves_map

{
    "ecosystem": "Ubuntu:Pro:20.04:LTS",
    "cves": [
        {
            "id": "CVE-2026-24515",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-25210",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ]
}

Ubuntu:Pro:22.04:LTS / libxmltok

Package

Name: libxmltok
Purl: pkg:deb/ubuntu/libxmltok@1.2-4ubuntu0.22.04.1~esm6?arch=source&distro=esm-apps/jammy

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

1.2-4ubuntu0.22.04.1~esm6

Affected versions

1.*

1.2-4

1.2-4ubuntu0.22.04.1~esm1

1.2-4ubuntu0.22.04.1~esm2

1.2-4ubuntu0.22.04.1~esm3

1.2-4ubuntu0.22.04.1~esm4

1.2-4ubuntu0.22.04.1~esm5

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libxmltok1",
            "binary_version": "1.2-4ubuntu0.22.04.1~esm6"
        },
        {
            "binary_name": "libxmltok1-dev",
            "binary_version": "1.2-4ubuntu0.22.04.1~esm6"
        }
    ],
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8023-1.json"

cves_map

{
    "ecosystem": "Ubuntu:Pro:22.04:LTS",
    "cves": [
        {
            "id": "CVE-2026-24515",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-25210",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ]
}

Ubuntu:Pro:24.04:LTS / libxmltok

Package

Name: libxmltok
Purl: pkg:deb/ubuntu/libxmltok@1.2-4.1ubuntu2.24.0.4.1+esm4?arch=source&distro=esm-apps/noble

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

1.2-4.1ubuntu2.24.0.4.1+esm4

Affected versions

1.*

1.2-4ubuntu1

1.2-4.1ubuntu1

1.2-4.1ubuntu2

1.2-4.1ubuntu2.24.0.4.1+esm1

1.2-4.1ubuntu2.24.0.4.1+esm2

1.2-4.1ubuntu2.24.0.4.1+esm3

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libxmltok1-dev",
            "binary_version": "1.2-4.1ubuntu2.24.0.4.1+esm4"
        },
        {
            "binary_name": "libxmltok1t64",
            "binary_version": "1.2-4.1ubuntu2.24.0.4.1+esm4"
        }
    ],
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8023-1.json"

cves_map

{
    "ecosystem": "Ubuntu:Pro:24.04:LTS",
    "cves": [
        {
            "id": "CVE-2026-24515",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-25210",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ]
}