Busybox: busybox: tar extraction-root escape via deferred symlink/hardlink creation bypasses cve-2026-26158 fix
Summary
| CVE | CVE-2026-108119 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-09 17:16:46 UTC |
| Updated | 2026-10-09 17:42:00 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 6.3 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H
EPSS: 0.001230000 probability, percentile 0.018790000 (date 2026-10-10)
Problem Types: CWE-59 | CWE-59 Improper Link Resolution Before File Access ('Link Following')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 6.3 | MEDIUM | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H |
| 3.1 | CNA | CVSS | 6.3 | MEDIUM | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H |
CVSS v3.1 Breakdown
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Hardened Images | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/security/cve/CVE-2026-108119 | [email protected] | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank TAE3 for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-10-09T14:03:56.635Z | Reported to Red Hat. |
| CNA | 2026-10-09T15:31:42.723Z | Made public. |
Workarounds
CNA: 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.