CVE-2026-42511 — HIGH (8.1)

Vulnerability 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.

CVSS Score

8.1

HIGH

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
Freebsd	Freebsd	13.5

Related Weaknesses (CWE)

CWE-149

References

https://security.freebsd.org/advisories/FreeBSD-SA-26:12.dhclient.ascVendor Advisory

FAQ

What is CVE-2026-42511?

CVE-2026-42511 is a vulnerability with a CVSS score of 8.1 (HIGH). 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 d...

How severe is CVE-2026-42511?

CVE-2026-42511 has been rated HIGH with a CVSS base score of 8.1/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-42511?

Check the references section above for vendor advisories and patch information. Affected products include: Freebsd Freebsd.