USN-8954-1

Ali Firas discovered that zlib incorrectly handled certain non-blocking write operations. An attacker could possibly use this issue to trigger a heap buffer overflow, resulting in a denial of service or arbitrary code execution.

References

Affected packages

Ubuntu:24.04:LTS / zlib

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

1:1.3.dfsg-3.1ubuntu2.3

Affected versions

1:1.*

1:1.2.13.dfsg-1ubuntu5

1:1.3.dfsg-3ubuntu1

1:1.3.dfsg-3.1ubuntu1

1:1.3.dfsg-3.1ubuntu2

1:1.3.dfsg-3.1ubuntu2.1

1:1.3.dfsg-3.1ubuntu2.2

Ecosystem specific

{
    "availability":  "No subscription required",
    "binaries":  [
        {
            "binary_name":  "lib32z1",
            "binary_version":  "1:1.3.dfsg-3.1ubuntu2.3"
        },
        {
            "binary_name":  "lib64z1",
            "binary_version":  "1:1.3.dfsg-3.1ubuntu2.3"
        },
        {
            "binary_name":  "libminizip1t64",
            "binary_version":  "1:1.3.dfsg-3.1ubuntu2.3"
        },
        {
            "binary_name":  "libx32z1",
            "binary_version":  "1:1.3.dfsg-3.1ubuntu2.3"
        },
        {
            "binary_name":  "minizip",
            "binary_version":  "1:1.3.dfsg-3.1ubuntu2.3"
        },
        {
            "binary_name":  "zlib1g",
            "binary_version":  "1:1.3.dfsg-3.1ubuntu2.3"
        }
    ]
}

Database specific

cves_map

{
    "cves":  [
        {
            "id":  "CVE-2026-85091",
            "severity":  [
                {
                    "score":  "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H",
                    "type":  "CVSS_V3"
                },
                {
                    "score":  "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N",
                    "type":  "CVSS_V4"
                },
                {
                    "score":  "medium",
                    "type":  "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem":  "Ubuntu:24.04:LTS"
}

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8954-1.json"

Ubuntu:26.10 / zlib

Package

Name: zlib
Purl: pkg:deb/ubuntu/zlib?arch=source&distro=stonking

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

1:1.3.dfsg+really1.3.2-3ubuntu1.1

Affected versions

1:1.*

1:1.3.dfsg+really1.3.1-1ubuntu3

1:1.3.dfsg+really1.3.2-3ubuntu1

Ecosystem specific

{
    "availability":  "No subscription required",
    "binaries":  [
        {
            "binary_name":  "lib32z1",
            "binary_version":  "1:1.3.dfsg+really1.3.2-3ubuntu1.1"
        },
        {
            "binary_name":  "lib64z1",
            "binary_version":  "1:1.3.dfsg+really1.3.2-3ubuntu1.1"
        },
        {
            "binary_name":  "libminizip1t64",
            "binary_version":  "1:1.3.dfsg+really1.3.2-3ubuntu1.1"
        },
        {
            "binary_name":  "libx32z1",
            "binary_version":  "1:1.3.dfsg+really1.3.2-3ubuntu1.1"
        },
        {
            "binary_name":  "minizip",
            "binary_version":  "1:1.3.dfsg+really1.3.2-3ubuntu1.1"
        },
        {
            "binary_name":  "zlib1g",
            "binary_version":  "1:1.3.dfsg+really1.3.2-3ubuntu1.1"
        }
    ]
}

Database specific

cves_map

{
    "cves":  [
        {
            "id":  "CVE-2026-85091",
            "severity":  [
                {
                    "score":  "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H",
                    "type":  "CVSS_V3"
                },
                {
                    "score":  "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N",
                    "type":  "CVSS_V4"
                },
                {
                    "score":  "medium",
                    "type":  "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem":  "Ubuntu:26.10"
}

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8954-1.json"

Ubuntu:26.04:LTS / zlib

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

1:1.3.dfsg+really1.3.1-1ubuntu3.2

Affected versions

1:1.*

1:1.3.dfsg+really1.3.1-1ubuntu2

1:1.3.dfsg+really1.3.1-1ubuntu3

1:1.3.dfsg+really1.3.1-1ubuntu3.1

Ecosystem specific

{
    "availability":  "No subscription required",
    "binaries":  [
        {
            "binary_name":  "lib32z1",
            "binary_version":  "1:1.3.dfsg+really1.3.1-1ubuntu3.2"
        },
        {
            "binary_name":  "lib64z1",
            "binary_version":  "1:1.3.dfsg+really1.3.1-1ubuntu3.2"
        },
        {
            "binary_name":  "libminizip1t64",
            "binary_version":  "1:1.3.dfsg+really1.3.1-1ubuntu3.2"
        },
        {
            "binary_name":  "libx32z1",
            "binary_version":  "1:1.3.dfsg+really1.3.1-1ubuntu3.2"
        },
        {
            "binary_name":  "minizip",
            "binary_version":  "1:1.3.dfsg+really1.3.1-1ubuntu3.2"
        },
        {
            "binary_name":  "zlib1g",
            "binary_version":  "1:1.3.dfsg+really1.3.1-1ubuntu3.2"
        }
    ]
}

Database specific

cves_map

{
    "cves":  [
        {
            "id":  "CVE-2026-85091",
            "severity":  [
                {
                    "score":  "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H",
                    "type":  "CVSS_V3"
                },
                {
                    "score":  "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N",
                    "type":  "CVSS_V4"
                },
                {
                    "score":  "medium",
                    "type":  "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem":  "Ubuntu:26.04:LTS"
}

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8954-1.json"