CVE-2026-42512

Description

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.

PUBLISHED Reserved 2026-04-28 | Published 2026-04-30 | Updated 2026-05-01 | Assigner freebsd

Problem types

CWE-122: Heap-based Buffer Overflow

Product status

Credits

Joshua Rogers of AISLE Research Team finder

References

security.freebsd.org/...sories/FreeBSD-SA-26:15.dhclient.asc vendor-advisory

cve.org (CVE-2026-42512)

nvd.nist.gov (CVE-2026-42512)

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