CVE-2026-108119

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

Published Oct 9, 2026 CVSS 3.1 · 6.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

Vendor Workaround

Avoid extracting tar archives from untrusted sources using busybox, especially with elevated privileges or into a directory that will be reused for a subsequent extraction. If untrusted archives must be processed, extract into a freshly created, isolated directory with minimal privileges on a single filesystem boundary and discard it (including any links left on disk) after each extraction.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Redhat rhel Els
CPEs cpe:/o:redhat:enterprise_linux:6 cpe:/o:redhat:rhel_els:6
Vendors & Products Redhat rhel Els
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Busybox
Busybox busybox
Redhat hardened Images
Vendors & Products Busybox
Busybox busybox
Redhat hardened Images
Type Values Removed Values Added
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.
Title Busybox: busybox: tar extraction-root escape via deferred symlink/hardlink creation bypasses cve-2026-26158 fix
First Time appeared Redhat
Redhat enterprise Linux
Redhat hummingbird
Weaknesses CWE-59
CPEs cpe:/a:redhat:hummingbird:1
cpe:/o:redhat:enterprise_linux:6
Vendors & Products Redhat
Redhat enterprise Linux
Redhat hummingbird
References
Metrics cvssV3_1

{'score': 6.3, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 5, 2026, 3:56 PM
Reserved
Oct 9, 2026, 2:09 PM
Status
Awaiting Analysis
Published
Oct 9, 2026, 5:16 PM
Modified
Nov 5, 2026, 4:17 PM
Severity
Moderate
Public date
Oct 9, 2026, 3:31 PM