CVE-2026-90954: BusyBox's dpkg-deb archive extraction
Affects busyboxSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 29 Oct 2026, 01:12 UTC
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 14 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10busyboxpkg:deb/ubuntu/busybox?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSbusyboxpkg:deb/ubuntu/busybox?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSbusyboxpkg:deb/ubuntu/busybox?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSbusyboxpkg:deb/ubuntu/busybox?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 20.04 LTSbusyboxpkg:deb/ubuntu/busybox?arch=source&distro=focalOther threats | Affected
| Fixed in– |
Ubuntu Pro 18.04 LTSbusyboxpkg:deb/ubuntu/busybox?arch=source&distro=esm-infra/bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Do not use BusyBox dpkg-deb to extract untrusted .deb packages. Instead, use the Debian reference dpkg-deb implementation, which correctly treats the extraction root as a boundary and is not vulnerable. If BusyBox dpkg-deb must be used, inspect .deb archives for multiple data.tar members before extraction, as legitimate .deb packages contain exactly one data.tar member. Avoid extracting untrusted .deb files with BusyBox dpkg-deb until a fix is available.
Description
A vulnerability in BusyBox's dpkg-deb archive extraction allows crafted .deb packages with multiple data.tar members to write files outside the intended extraction directory. This occurs because the ar archive handler flushes deferred symlinks after each archive member, enabling a symlink pointing to an absolute path to be activated prematurely. An attacker can exploit this to write arbitrary files to arbitrary locations during extraction.