UBUNTU-CVE-2026-124741: Buffer Overflow
A flaw was found in BusyBox. The udhcpc6 DHCPv6 client does not properly validate the size of network options sent by a server before copying them into memory. A malicious DHCPv6 server on the local network can exploit this flaw by sending a crafted reply, triggering a stack-based buffer overflow. This vulnerability could allow an attacker to achieve arbitrary code execution with root privileges or cause a denial of service (DoS) crash.
Affected Software
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Systems running the BusyBox udhcpc6 DHCPv6 client are exposed when they accept DHCPv6 replies from a malicious server on their local network. The affected software identified here is ubuntu/busybox.
What does an attacker need to exploit it?
An attacker needs to operate or impersonate a DHCPv6 server on the local network and send a crafted DHCPv6 reply to the vulnerable client. The issue is triggered by improperly sized network options in that reply.
What is the potential impact of successful exploitation?
A successful attack can cause a denial-of-service crash or potentially enable arbitrary code execution with root privileges.