CVE-2026-29004 BusyBox DHCPv6 Client Heap Buffer Overflow via DNS_SERVERS
Network-adjacent attackers can trigger heap buffer overflow in BusyBox DHCPv6 client via crafted responses, leading to code execution or denial of service on embedded systems.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-29004?
CVE-2026-29004 is a high-severity memory corruption vulnerability in vda-linux busybox_mirror, published on 4 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
BusyBox before commit 42202bf contains a heap buffer overflow vulnerability in the DHCPv6 client (udhcpc6) DNS_SERVERS option handler in networking/udhcp/d6_dhcpc.c that allows network-adjacent attackers to trigger memory corruption by sending a crafted DHCPv6 response with a malformed D6_OPT_DNS_SERVERS option. Attackers can exploit incorrect heap buffer allocation calculations in the option_to_env() function to cause denial of service or achieve arbitrary code execution on embedded systems without heap hardening.
Which versions are affected by CVE-2026-29004?
Linux distribution packages (6)
busybox Red Hat:hummingbird:1 | All versions | 0:1.37.0-7.3.hum1 |
busybox-petitboot Red Hat:hummingbird:1 | All versions | 0:1.37.0-7.3.hum1 |
busybox-shared Red Hat:hummingbird:1 | All versions | 0:1.37.0-7.3.hum1 |
busybox SUSE:Linux Enterprise Server 16.0 | All versions | 1.37.0-160000.6.1 |
busybox SUSE:Linux Enterprise Server for SAP applications 16.0 | All versions | 1.37.0-160000.6.1 |
busybox openSUSE:Tumbleweed | All versions | 1.37.0-11.1 |
How do I fix CVE-2026-29004?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-29004 being exploited?
There is no known exploitation of CVE-2026-29004 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-29004, DEBIAN-CVE-2026-29004, ECHO-4d14-5e51-2c9b, GHSA-vx55-mmvv-p227, OESA-2026-2357, RHSA-2026:30652 and 9 more.