CVE-2026-108119
Busybox: busybox: tar extraction-root escape via deferred symlink/hardlink creation bypasses cve-2026-26158 fix
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.
Fixes and workarounds
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.
Source: CNA: redhatAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| Red Hat Hardened Images Red Hat busybox-main
https://catalog.redhat.com/software/containers/ |
≥ 1.37.0-9.4.hum1; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 6 Red Hat busybox
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 6.3 medium |
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H | CNA: redhat |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://access.redhat.com/errata/RHSA-2026:81391CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-108119CNA: redhat · vdb-entry, x_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2548611CNA: redhat · issue-tracking, x_refsource_REDHAT
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