CVE-2026-42511

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.

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

Problem types

CWE-149: Improper Neutralization of Quoting Syntax

Product status

Credits

Joshua Rogers of AISLE Research Team finder

References

security.freebsd.org/...sories/FreeBSD-SA-26:12.dhclient.asc vendor-advisory

cve.org (CVE-2026-42511)

nvd.nist.gov (CVE-2026-42511)

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