USN-8463-1

It was discovered that LibVNCServer had a memory leak in the client cleanup function. An attacker could possibly use this issue to cause LibVNCServer to consume memory, leading to a denial of service. This issue only affected Ubuntu 22.04 LTS. (CVE-2020-29260)

It was discovered that LibVNCServer did not properly validate bounds when handling UltraZip encoding subrectangles. A remote attacker could possibly use this issue to obtain sensitive information or cause a denial of service. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 25.04. (CVE-2026-32853)

It was discovered that LibVNCServer did not properly validate return values in the HTTP proxy handlers. A remote attacker could possibly use this issue to cause LibVNCServer to crash, resulting in a denial of service. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 25.04. (CVE-2026-32854)

It was discovered that LibVNCServer did not properly handle Tight encoding gradient filter rectangles. A remote attacker could use this issue to cause LibVNCServer to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-44988)

References

Affected packages

Ubuntu:22.04:LTS / libvncserver

Package

Name: libvncserver
Purl: pkg:deb/ubuntu/libvncserver?arch=source&distro=jammy

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

0.9.13+dfsg-3ubuntu0.1

Affected versions

0.*

0.9.13+dfsg-3

0.9.13+dfsg-3build1

0.9.13+dfsg-3build2

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libvncclient1",
            "binary_version": "0.9.13+dfsg-3ubuntu0.1"
        },
        {
            "binary_name": "libvncserver1",
            "binary_version": "0.9.13+dfsg-3ubuntu0.1"
        }
    ],
    "availability": "No subscription required"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8463-1.json"

cves_map

{
    "ecosystem": "Ubuntu:22.04:LTS",
    "cves": [
        {
            "id": "CVE-2020-29260",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "low",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-32853",
            "severity": [
                {
                    "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N",
                    "type": "CVSS_V4"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-32854",
            "severity": [
                {
                    "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
                    "type": "CVSS_V4"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-44988",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ]
}

Ubuntu:24.04:LTS / libvncserver

Package

Name: libvncserver
Purl: pkg:deb/ubuntu/libvncserver?arch=source&distro=noble

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

0.9.14+dfsg-1ubuntu0.1

Affected versions

0.*

0.9.14+dfsg-1

0.9.14+dfsg-1build1

0.9.14+dfsg-1build2

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libvncclient1",
            "binary_version": "0.9.14+dfsg-1ubuntu0.1"
        },
        {
            "binary_name": "libvncserver1",
            "binary_version": "0.9.14+dfsg-1ubuntu0.1"
        }
    ],
    "availability": "No subscription required"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8463-1.json"

cves_map

{
    "ecosystem": "Ubuntu:24.04:LTS",
    "cves": [
        {
            "id": "CVE-2026-32853",
            "severity": [
                {
                    "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N",
                    "type": "CVSS_V4"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-32854",
            "severity": [
                {
                    "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
                    "type": "CVSS_V4"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-44988",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ]
}

Ubuntu:25.10 / libvncserver

Package

Name: libvncserver
Purl: pkg:deb/ubuntu/libvncserver?arch=source&distro=questing

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

0.9.15+dfsg-1ubuntu0.1

Affected versions

0.*

0.9.14+dfsg-1build2

0.9.15+dfsg-1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libvncclient1",
            "binary_version": "0.9.15+dfsg-1ubuntu0.1"
        },
        {
            "binary_name": "libvncserver1",
            "binary_version": "0.9.15+dfsg-1ubuntu0.1"
        }
    ],
    "availability": "No subscription required"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8463-1.json"

cves_map

{
    "ecosystem": "Ubuntu:25.10",
    "cves": [
        {
            "id": "CVE-2026-32853",
            "severity": [
                {
                    "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N",
                    "type": "CVSS_V4"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-32854",
            "severity": [
                {
                    "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
                    "type": "CVSS_V4"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        },
        {
            "id": "CVE-2026-44988",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ]
}

Ubuntu:26.04:LTS / libvncserver

Package

Name: libvncserver
Purl: pkg:deb/ubuntu/libvncserver?arch=source&distro=resolute

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

0.9.15+dfsg-3ubuntu0.1

Affected versions

0.*

0.9.15+dfsg-1

0.9.15+dfsg-2

0.9.15+dfsg-3

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "libvncclient1",
            "binary_version": "0.9.15+dfsg-3ubuntu0.1"
        },
        {
            "binary_name": "libvncserver1",
            "binary_version": "0.9.15+dfsg-3ubuntu0.1"
        }
    ],
    "availability": "No subscription required"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8463-1.json"

cves_map

{
    "ecosystem": "Ubuntu:26.04:LTS",
    "cves": [
        {
            "id": "CVE-2026-44988",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
                    "type": "CVSS_V3"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ]
}