CVE-2026-42512

CVE-2026-42512: Remotely triggerable out-of-bounds heap write in dhclient

Vendor Freebsd
Product FreeBSD
Weakness CWE-122
Published April 30, 2026
Last update May 1, 2026

CVSS base score

What the vulnerability does

01Description

As dhclient is building an environment to pass to dhclient-script, it may need to resize the array of string pointers. The code which expands the array incorrectly calculates its new size when requesting memory, resulting in a heap buffer overrun. A specially crafted packet can cause dhclient to overrun its buffer of environment entries. This can result in a crash, but it may be possible to leverage this bug to achieve remote code execution.

Key dates

02Disclosure timeline

April 30, 2026 CVE published
May 1, 2026 Record updated