CVE-2026-26158

Busybox: busybox: arbitrary file modification and privilege escalation via unvalidated tar archive entries

publishedCWE-73

A flaw was found in BusyBox. This vulnerability allows an attacker to modify files outside of the intended extraction directory by crafting a malicious tar archive containing unvalidated hardlink or symlink entries. If the tar archive is extracted with elevated privileges, this flaw can lead to privilege escalation, enabling an attacker to gain unauthorized access to critical system files.

Technical severity7.0 highCVSS 3.1 · CNA: redhat

Published2026-02-11Source updated 2026-11-04

Collected2026-11-053 attributed sources

Fixes and workarounds

Workaround

As a prevention measure, avoid extracting tar archives from untrusted sources using BusyBox, especially when operating with elevated privileges. If processing untrusted archives is unavoidable, ensure that the extraction process is performed within a strictly sandboxed environment with minimal permissions. This operational control reduces the risk of arbitrary file modification and privilege escalation.

Source: CNA: redhat

Fix

RHSA-2026:13831: Red Hat Hardened Images

Source: ADP: redhat-SADP

Workaround

Source: ADP: redhat-SADP

Affected products and versions

Affected products, source version ranges and reporting authorities
Product	Versions	Authority
Red Hat Hardened Images Red Hat `busybox-main` https://catalog.redhat.com/software/containers/	≥ 1.37.0-7.2.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: unknown	CNA: redhat
RUGGEDCOM RST2428P Siemens	≥ 0; < V4.0 (affected, custom) Other versions: unknown	ADP: siemens-SADP
Red Hat Hardened Images Red Hat `busybox-main` https://access.redhat.com/downloads/content/package-browser/	≥ 1.37.0-7.2.hum1; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 6 Red Hat `busybox` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unknown	ADP: redhat-SADP

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / score	Vector	Authority
3.1 / 7.0 high	`CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H`	CNA: redhat
3.1 / 7.0 high	`CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H`	ADP: redhat-SADP
3.1 / 7.0 high	`CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H`	NVD: [email protected]
3.1 / 7.0 high	`CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H`	NVD: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

https://access.redhat.com/errata/RHSA-2026:13831CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-26158CNA: redhat · vdb-entry, x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2439040CNA: redhat · issue-tracking, x_refsource_REDHAT
https://git.busybox.net/busybox/commit/archival?id=3fb6b31c716669e12f75a2accd31bb7685b1a1cbCNA: redhat
https://cert-portal.siemens.com/productcert/html/ssa-253495.htmlADP: siemens-SADP
https://access.redhat.com/security/cve/CVE-2026-26158ADP: redhat-SADP · vdb-entry, x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2439040ADP: redhat-SADP · issue-tracking, x_refsource_REDHAT
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26158.jsonADP: redhat-SADP · x_sadp-csaf-vex
https://access.redhat.com/errata/RHSA-2026:13831ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:13831[email protected]
https://access.redhat.com/security/cve/CVE-2026-26158[email protected]
https://bugzilla.redhat.com/show_bug.cgi?id=2439040[email protected]
https://git.busybox.net/busybox/commit/archival?id=3fb6b31c716669e12f75a2accd31bb7685b1a1cb[email protected]
https://access.redhat.com/errata/RHSA-2026:138310b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/security/cve/CVE-2026-261580b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://bugzilla.redhat.com/show_bug.cgi?id=24390400b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://cert-portal.siemens.com/productcert/html/ssa-253495.html0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26158.json0b0ca135-0b70-47e7-9f44-1890c2a1c46c

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