Remote code execution via malicious DHCP options_CVE-2026-42511

7.3 / 10

HIGH

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

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.

Basic Information

ID CVE-2026-42511

Source freebsd

Published Apr 30, 2026 at 06:56

Modified Apr 30, 2026 at 13:06

Affected Product

Vendor FreeBSD

Product FreeBSD

Version 15.0-RELEASE

Affected Versions FreeBSD FreeBSD 15.0-RELEASE
FreeBSD FreeBSD 14.4-RELEASE
FreeBSD FreeBSD 14.3-RELEASE
FreeBSD FreeBSD 13.5-RELEASE

CWE Classification

CWE-149

References

security.freebsd.org /advisories/FreeBSD-SA-26:12.dhclient.asc

{
    "lastseen": "",
    "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.\n\nA rogue DHCP server may be able to execute arbirary code as root on a system running dhclient.",
    "published": "2026-04-30T06:56:36.929Z",
    "modified": "2026-04-30T13:06:53.628Z",
    "type": "cve",
    "title": "Remote code execution via malicious DHCP options",
    "source": "freebsd",
    "references": "https://security.freebsd.org/advisories/FreeBSD-SA-26:12.dhclient.asc",
    "id": "CVE-2026-42511",
    "bulletinFamily": "",
    "cwe": [
        "CWE-149"
    ],
    "cvelist": null,
    "sourceData": "FreeBSD FreeBSD 15.0-RELEASE\nFreeBSD FreeBSD 14.4-RELEASE\nFreeBSD FreeBSD 14.3-RELEASE\nFreeBSD FreeBSD 13.5-RELEASE",
    "sourceHref": "",
    "cvss": {
        "score": 7.3,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "FreeBSD",
    "version": "15.0-RELEASE",
    "vendor": "FreeBSD",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}