CVE-2026-108119: Busybox: busybox: tar extraction-root escape via deferred symlink/hardlink creation bypasses cve-2026-26158 fix

Severity: medium (CVSS 6.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-09 · updated 2026-10-13
Weakness: CWE-59

Description

A flaw was found in busybox. The tar applet's deferred link-creation handling for symlink and hardlink entries with unsafe-looking targets does not validate that the resolved destination remains inside the extraction directory once the deferred link is created. An attacker can craft a tar archive using a symlink target of exactly '..' combined with a deferred hardlink to create a new file outside the extraction directory, or reuse an extraction directory across two archives to replace an existing file outside it. If the archive is extracted with elevated privileges, this flaw can lead to privilege escalation or arbitrary code execution.

Affected products

Red Hat Enterprise Linux 6: all versions
Red Hat Hardened Images: all versions — fixed in 1.37.0-9.4.hum1

How to fix

Upgrade to a fixed version: Red Hat Hardened Images 1.37.0-9.4.hum1. Check the vendor advisory for mitigations.

References

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