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CVE-2026-90954

CVE-2026-90954 · Busybox: busybox: dpkg-deb extraction-root escape via per-ar-member deferred symlink flush

This page contains facts from public vulnerability sources. Check the original advisory before updating.

A flaw was found in BusyBox's dpkg-deb archive extraction. The ar archive handler flushes deferred symlinks after each archive member, unlike the tar, cpio, and unzip handlers which flush once after the last member. A specially crafted .deb archive with two data.tar members can exploit this ordering: the first member declares a symlink pointing to an absolute path (e.g., '/'), which is deferred as unsafe but flushed after the first member. The second member declares a regular file whose path traverses the now-live symlink, resulting in a file being written outside the intended extraction directory. This could allow an attacker to write arbitrary files to arbitrary locations when a user extracts a crafted .deb package.

CVSS 7.8 · High · EPSS 0.2%

Published
Updated

Stack: system

Affected products and versions

  • red hat hardened images

    No fix published

  • busybox Debian:12

    Versions
    • 1:1.35.0-4
    • 1:1.35.0-4+deb12u1
    • 1:1.36.0-1~exp1
    • 1:1.36.1-1
    • 1:1.36.1-2
    • 1:1.36.1-3
    • 1:1.36.1-3.1
    • 1:1.36.1-4
    • 1:1.36.1-5
    • 1:1.36.1-6
    • 1:1.36.1-6~exp.1
    • 1:1.36.1-7
    • 1:1.36.1-8
    • 1:1.36.1-9
    • 1:1.37.0-1
    • 1:1.37.0-10
    • 1:1.37.0-10.1
    • 1:1.37.0-2
    • 1:1.37.0-3
    • 1:1.37.0-4
    • 1:1.37.0-5
    • 1:1.37.0-6
    • 1:1.37.0-7
    • 1:1.37.0-8
    • 1:1.37.0-9
    • 1:1.38.0-1
    • 1:1.38.0-2
    • 1:1.38.0-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • busybox Debian:13

    Versions
    • 1:1.37.0-10
    • 1:1.37.0-10.1
    • 1:1.37.0-6
    • 1:1.37.0-7
    • 1:1.37.0-8
    • 1:1.37.0-9
    • 1:1.38.0-1
    • 1:1.38.0-2
    • 1:1.38.0-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • busybox Debian:14

    Versions
    • 1:1.37.0-10
    • 1:1.37.0-10.1
    • 1:1.37.0-6
    • 1:1.37.0-7
    • 1:1.37.0-8
    • 1:1.37.0-9
    • 1:1.38.0-1
    • 1:1.38.0-2
    • 1:1.38.0-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • busybox Ubuntu:Pro:14.04:LTS

    Versions
    • 1:1.20.0-8.1ubuntu1
    • 1:1.20.0-9ubuntu1
    • 1:1.20.0-9ubuntu2
    • 1:1.21.0-1ubuntu1
    • 1:1.21.0-1ubuntu1.4
    • 1:1.21.0-1ubuntu1.4+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • busybox Ubuntu:Pro:16.04:LTS

    Versions
    • 1:1.22.0-15ubuntu1
    • 1:1.22.0-15ubuntu1.4
    • 1:1.22.0-15ubuntu1.4+esm1
    • 1:1.22.0-15ubuntu1.4+esm2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • busybox Ubuntu:Pro:18.04:LTS

    Versions
    • 1:1.22.0-19ubuntu2
    • 1:1.27.2-1ubuntu3
    • 1:1.27.2-1ubuntu4
    • 1:1.27.2-2ubuntu2
    • 1:1.27.2-2ubuntu3
    • 1:1.27.2-2ubuntu3.1
    • 1:1.27.2-2ubuntu3.2
    • 1:1.27.2-2ubuntu3.3
    • 1:1.27.2-2ubuntu3.4
    • 1:1.27.2-2ubuntu3.4+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • busybox Ubuntu:20.04:LTS

    Versions
    • 1:1.30.1-4ubuntu4
    • 1:1.30.1-4ubuntu5
    • 1:1.30.1-4ubuntu6
    • 1:1.30.1-4ubuntu6.1
    • 1:1.30.1-4ubuntu6.2
    • 1:1.30.1-4ubuntu6.3
    • 1:1.30.1-4ubuntu6.4
    • 1:1.30.1-4ubuntu6.5
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • busybox Ubuntu:22.04:LTS

    Versions
    • 1:1.30.1-6ubuntu3
    • 1:1.30.1-7ubuntu1
    • 1:1.30.1-7ubuntu2
    • 1:1.30.1-7ubuntu3
    • 1:1.30.1-7ubuntu3.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • busybox Ubuntu:24.04:LTS

    Versions
    • 1:1.36.1-3ubuntu1
    • 1:1.36.1-6ubuntu1
    • 1:1.36.1-6ubuntu3
    • 1:1.36.1-6ubuntu3.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • busybox Ubuntu:26.10

    Versions
    • 1:1.37.0-7ubuntu1
    • 1:1.37.0-10.1ubuntu2
    • 1:1.37.0-10.1ubuntu3
    • 1:1.38.0-3ubuntu1
    • 1:1.38.0-3ubuntu3
    • 1:1.38.0-3ubuntu4
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • busybox Ubuntu:26.04:LTS

    Versions
    • 1:1.37.0-4ubuntu1
    • 1:1.37.0-7ubuntu1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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