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Vulnerability · Published Aug 3, 2026 · Assigned by redhat

CVE-2026-18508Tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite

Medium 4.4

In plain English

A medium-severity security flaw in Red Hat Discovery 2 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.4Medium
Exploit odds (30 days)0.1%top 96.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:10tar2:1.35-13.el10_2ALSA-2026:61586
AlmaLinux:8tar2:1.30-13.el8_10ALSA-2026:70390
AlmaLinux:9tar2:1.34-13.el9_8ALSA-2026:61581
Debian:12tarno fix listedDEBIAN-CVE-2026-18508
Debian:13tarno fix listedDEBIAN-CVE-2026-18508
Debian:14tarno fix listedDEBIAN-CVE-2026-18508
Rocky Linux:10tar2:1.35-13.el10_2RLSA-2026:61586
Rocky Linux:8tar2:1.30-13.el8_10RLSA-2026:70390
Rocky Linux:9tar2:1.34-13.el9_8RLSA-2026:61581
Ubuntu:22.04:LTStarno fix listedUBUNTU-CVE-2026-18508
Ubuntu:24.04:LTStarno fix listedUBUNTU-CVE-2026-18508
Ubuntu:26.04:LTStarno fix listedUBUNTU-CVE-2026-18508
Ubuntu:26.10tarno fix listedUBUNTU-CVE-2026-18508

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat Enterprise Linux 10 see references
Red Hat Red Hat Enterprise Linux 8 see references
Red Hat Red Hat Enterprise Linux 9 see references
Red Hat Red Hat Discovery 2 see references
Red Hat Red Hat Hardened Images see references
Red Hat Red Hat Update Infrastructure 5 see references
Red Hat Red Hat Update Infrastructure 5 see references
Red Hat Red Hat Update Infrastructure 5 see references
Red Hat Red Hat Update Infrastructure 5 see references
Red Hat Red Hat Update Infrastructure 5 see references
Red Hat Red Hat Enterprise Linux 6 see references
Red Hat Red Hat Enterprise Linux 7 see references
Red Hat Red Hat Hardened Images see references
Red Hat Red Hat Hardened Images see references
Red Hat Red Hat Hardened Images see references
Red Hat Red Hat Hardened Images see references
Red Hat Red Hat Hardened Images see references
Red Hat Red Hat Hardened Images see references
Red Hat Red Hat Hardened Images see references
Red Hat Red Hat Hardened Images see references
Red Hat Red Hat Hardened Images see references
Red Hat Red Hat Hardened Images see references
Red Hat Red Hat OpenShift Container Platform 4 see references
Red Hat Red Hat OpenShift Container Platform 4 see references
Red Hat Red Hat OpenShift Container Platform 5 see references

Weakness: CWE-59 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

References