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.
History

Thu, 30 Apr 2026 13:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 30 Apr 2026 11:45:00 +0000

Type Values Removed Values Added
First Time appeared Freebsd
Freebsd freebsd
Vendors & Products Freebsd
Freebsd freebsd

Thu, 30 Apr 2026 09:00:00 +0000

Type Values Removed Values Added
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.
Title Remotely triggerable out-of-bounds heap write in dhclient
Weaknesses CWE-122
References

cve-icon MITRE

Status: PUBLISHED

Assigner: freebsd

Published:

Updated: 2026-04-30T13:09:57.171Z

Reserved: 2026-04-28T05:31:44.956Z

Link: CVE-2026-42512

cve-icon Vulnrichment

Updated: 2026-04-30T13:09:53.917Z

cve-icon NVD

Status : Received

Published: 2026-04-30T09:16:03.373

Modified: 2026-04-30T09:16:03.373

Link: CVE-2026-42512

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-30T11:30:05Z