Description
A flaw was found in BusyBox's httpd web server. When configured with system password authentication, a user existence oracle may exist in certain build configurations. An attacker could distinguish existing from non-existing usernames by observing authentication failure behavior. Impact is limited to username enumeration and requires non-default compile options or uncommon password file states; default BusyBox builds with shadow password support are not affected.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat Hardened Images | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | busybox | No fix yet | — |
| Debian 13 | busybox | No fix yet | — |
| Debian 12 | busybox | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | busybox | No fix yet | — |
| Ubuntu 26.04 LTS | busybox | No fix yet | — |
| Ubuntu 24.04 LTS | busybox | No fix yet | — |
| Ubuntu 22.04 LTS | busybox | No fix yet | — |
| Ubuntu 20.04 LTS | busybox | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | busybox | No fix yet | — |
| Ubuntu Pro 16.04 LTS | busybox | No fix yet | — |
| Ubuntu Pro 14.04 LTS | busybox | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | busybox | 1.38.0-4.1 | openSUSE-SU-2026:12376-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | busybox | No fix yet | — |
Advisories 2
- WID-SEC-2026-3914 BusyBox: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 11, 2026
- openSUSE-SU-2026:12376-1 busybox-1.38.0-4.1 on GA media SUSE / openSUSE Security Updates · Nov 2, 2026
References
- https://access.redhat.com/security/cve/CVE-2026-88834 vdb-entry
- RHBZ#2531348 issue-tracking