Vulnerability in FreeBSD

CVE-2026-42511

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 · last modified .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (33.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-42511: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

  • FreeBSD — versions 14.3, 13.5, 15.0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-42511?
CVE-2026-42511 is a high-severity vulnerability in FreeBSD, classified under CWE-149. CVSS score: 8.1/10. Published 2026-04-30.
How severe is CVE-2026-42511?
High severity. CVSS v3 base score is 8.1 out of 10.