CVE-2026-42511 Remote code execution via malicious DHCP options
A rogue DHCP server can inject directives into lease files, leading to arbitrary code execution as root when dhclient re-parses them.
- 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-2026-42511?
CVE-2026-42511 is a high-severity command injection vulnerability in Freebsd Freebsd, published on 30 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The BOOTP file field is written to the lease file without escaping embedded double-quotes, allowing injection of arbitrary dhclient.conf directives. When the lease file is subsequently re-parsed by dhclient, e.g., after a system restart, an attacker-controlled field from the lease is passed to dhclient-script(8), which evaluates it.
A rogue DHCP server may be able to execute arbirary code as root on a system running dhclient.
Weakness: CWE-149
Which versions are affected by CVE-2026-42511?
It affects 1 product.
Products include Freebsd Freebsd.
How do I fix CVE-2026-42511?
No fix has been published for CVE-2026-42511 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-42511 being exploited?
There is no known exploitation of CVE-2026-42511 in the wild and no public exploit code.
Other vulnerabilities in Freebsd Freebsd
Sources
Also known as GHSA-xg3v-hpwh-q32x.