CVE-2026-88829 Busybox: busybox: http request smuggling via pipelined requests in httpd reverse proxy
Attackers can bypass proxy path restrictions via pipelined requests to access arbitrary backend paths in BusyBox httpd reverse proxy configurations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-88829?
CVE-2026-88829 is a high-severity vulnerability in Red Hat Hardened Images, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A flaw was found in BusyBox httpd's reverse proxy feature. When the proxy is configured to forward requests matching a URL prefix to a backend server, only the first HTTP request on a TCP connection has its path rewritten. An attacker can send a pipelined second request that is relayed verbatim to the backend, bypassing the configured path restrictions. This allows accessing arbitrary paths on the backend server that were not intended to be exposed through the proxy.
Weakness: CWE-444
Which versions are affected by CVE-2026-88829?
How do I fix CVE-2026-88829?
No fix has been published for CVE-2026-88829 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-88829 being exploited?
There is no known exploitation of CVE-2026-88829 in the wild and no public exploit code.
Sources
Also known as AZL-109779, BELL-CVE-2026-88829, DEBIAN-CVE-2026-88829, GHSA-89f7-8rmh-f5q2, UBUNTU-CVE-2026-88829.