UBUNTU-CVE-2026-18508

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Source

https://ubuntu.com/security/CVE-2026-18508

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18508.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-18508

Upstream

CVE-2026-18508

Published

2026-08-03T16:16:00Z

Modified

2026-08-06T00:12:19Z

Severity

4.4 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.

References

Affected packages

Ubuntu:22.04:LTS

tar

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.34+dfsg-1build1

1.34+dfsg-1build2

1.34+dfsg-1build3

1.34+dfsg-1ubuntu0.1.22.04.1

1.34+dfsg-1ubuntu0.1.22.04.2

1.34+dfsg-1ubuntu0.1.22.04.3

1.34+dfsg-1ubuntu0.1.22.04.4

1.34+dfsg-1ubuntu0.1.22.04.5

1.34+dfsg-1ubuntu0.1.22.04.6

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "tar",
            "binary_version": "1.34+dfsg-1ubuntu0.1.22.04.6"
        },
        {
            "binary_name": "tar-scripts",
            "binary_version": "1.34+dfsg-1ubuntu0.1.22.04.6"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18508.json"

Ubuntu:24.04:LTS

tar

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.34+dfsg-1.2ubuntu1

1.34+dfsg-1.2ubuntu2

1.34+dfsg-1.3ubuntu1

1.34+dfsg-1.4

1.35+dfsg-2~build1

1.35+dfsg-2

1.35+dfsg-3

1.35+dfsg-3build1

1.35+dfsg-3ubuntu0.1

1.35+dfsg-3ubuntu0.2

1.35+dfsg-3ubuntu0.3

1.35+dfsg-3ubuntu0.4

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "tar",
            "binary_version": "1.35+dfsg-3ubuntu0.4"
        },
        {
            "binary_name": "tar-scripts",
            "binary_version": "1.35+dfsg-3ubuntu0.4"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18508.json"

Ubuntu:26.04:LTS

tar

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.35+dfsg-3.1build1

1.35+dfsg-3.1build2

1.35+dfsg-4

1.35+dfsg-4ubuntu0.1

1.35+dfsg-4ubuntu0.2

1.35+dfsg-4ubuntu0.3

1.35+dfsg-4ubuntu0.4

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "tar",
            "binary_version": "1.35+dfsg-4ubuntu0.4"
        },
        {
            "binary_name": "tar-scripts",
            "binary_version": "1.35+dfsg-4ubuntu0.4"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18508.json"

Ubuntu:Pro:14.04:LTS

tar

Package

Name: tar
Purl: pkg:deb/ubuntu/tar?arch=source&distro=esm-infra-legacy%2Ftrusty

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.26+dfsg-8

1.27-3

1.27-4

1.27.1-1

1.27.1-1ubuntu0.1

1.27.1-1ubuntu0.1+esm1

1.27.1-1ubuntu0.1+esm2

1.27.1-1ubuntu0.1+esm3

1.27.1-1ubuntu0.1+esm4

1.27.1-1ubuntu0.1+esm5

1.27.1-1ubuntu0.1+esm6

1.27.1-1ubuntu0.1+esm7

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "tar",
            "binary_version": "1.27.1-1ubuntu0.1+esm7"
        },
        {
            "binary_name": "tar-scripts",
            "binary_version": "1.27.1-1ubuntu0.1+esm7"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18508.json"

Ubuntu:Pro:16.04:LTS

tar

Package

Name: tar
Purl: pkg:deb/ubuntu/tar?arch=source&distro=esm-infra-legacy%2Fxenial

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.27.1-2

1.28-2ubuntu1

1.28-2.1

1.28-2.1ubuntu0.1

1.28-2.1ubuntu0.2

1.28-2.1ubuntu0.2+esm1

1.28-2.1ubuntu0.2+esm2

1.28-2.1ubuntu0.2+esm3

1.28-2.1ubuntu0.2+esm4

1.28-2.1ubuntu0.2+esm5

1.28-2.1ubuntu0.2+esm6

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "tar",
            "binary_version": "1.28-2.1ubuntu0.2+esm6"
        },
        {
            "binary_name": "tar-scripts",
            "binary_version": "1.28-2.1ubuntu0.2+esm6"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18508.json"

Ubuntu:Pro:18.04:LTS

tar

Package

Name: tar
Purl: pkg:deb/ubuntu/tar?arch=source&distro=esm-infra%2Fbionic

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.29b-2

1.29b-2ubuntu0.1

1.29b-2ubuntu0.2

1.29b-2ubuntu0.3

1.29b-2ubuntu0.4

1.29b-2ubuntu0.4+esm1

1.29b-2ubuntu0.4+esm2

1.29b-2ubuntu0.4+esm3

1.29b-2ubuntu0.4+esm4

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "tar",
            "binary_version": "1.29b-2ubuntu0.4+esm4"
        },
        {
            "binary_name": "tar-scripts",
            "binary_version": "1.29b-2ubuntu0.4+esm4"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18508.json"

Ubuntu:Pro:20.04:LTS

tar

Package

Name: tar
Purl: pkg:deb/ubuntu/tar?arch=source&distro=esm-infra%2Ffocal

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.30+dfsg-6

1.30+dfsg-7

1.30+dfsg-7ubuntu0.20.04.1

1.30+dfsg-7ubuntu0.20.04.2

1.30+dfsg-7ubuntu0.20.04.3

1.30+dfsg-7ubuntu0.20.04.4

1.30+dfsg-7ubuntu0.20.04.4+esm1

1.30+dfsg-7ubuntu0.20.04.4+esm2

1.30+dfsg-7ubuntu0.20.04.4+esm3

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "tar",
            "binary_version": "1.30+dfsg-7ubuntu0.20.04.4+esm3"
        },
        {
            "binary_name": "tar-scripts",
            "binary_version": "1.30+dfsg-7ubuntu0.20.04.4+esm3"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18508.json"