CVE-2026-124739 Busybox: httpd stack buffer overflow via an "i:" rule in a subdirectory httpd.conf
An attacker able to write a subdirectory httpd.conf can overflow a stack buffer in BusyBox httpd to run code or crash it.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Harmful if only installed
- No
- Needs a specific call
- No
- Fix
- None listed
What is CVE-2026-124739?
CVE-2026-124739 is a high-severity memory corruption vulnerability in Red Hat Enterprise Linux 6, published on 11 Nov 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A flaw was found in BusyBox. When the httpd web server processes subdirectory configuration files, an overly long index page name can trigger a stack-based buffer overflow. An attacker with permissions to write to a subdirectory configuration file could exploit this vulnerability to execute arbitrary code with elevated privileges or cause a denial of service (DoS) by crashing the server process.
Weakness: CWE-787
Which versions are affected by CVE-2026-124739?
An affected version is exposed as installed. No special setting or call is needed.
How do I fix CVE-2026-124739?
No fix has been published for CVE-2026-124739 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-124739 being exploited?
There is no known exploitation of CVE-2026-124739 in the wild and no public exploit code.
Sources
Also known as GHSA-cfm6-7rfg-w924, UBUNTU-CVE-2026-124739.