CVE-2026-90954
No fix known EPSS <1%CVSS 7.8
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.
Products: Red Hat Hardened Images
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Debian 12 | busybox | no fix |
| Debian 13 | busybox | no fix |
| Debian 14 | busybox | no fix |
| Ubuntu 20.04 LTS | busybox | no fix |
| Ubuntu 22.04 LTS | busybox | no fix |
| Ubuntu 24.04 LTS | busybox | no fix |
| Ubuntu 26.04 LTS | busybox | no fix |
| Ubuntu 26.10 | busybox | no fix |
| Ubuntu Pro 14.04 LTS | busybox | no fix |
| Ubuntu Pro 16.04 LTS | busybox | no fix |
| Ubuntu Pro 18.04 LTS | busybox | no fix |