---
id: CVE-2026-56116
title: >-
  dhcpcd through 10.3.2, fixed in commit 708b4a5, contains a memory leak
  vulnerability in the IPv6 Router Advertisement route information handling that
  allows an unauthenticated same-link attacker to cause denial of service by
  sending craf…
summary: >-
  dhcpcd through 10.3.2, fixed in commit 708b4a5, contains a memory leak
  vulnerability in the IPv6 Router Advertisement route information handling that
  allows an unauthenticated same-link attacker to cause denial of service by
  sending craf…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-401
vendor: dhcpcd_project
product: dhcpcd
affected:
  - 'dhcpcd >= 10.0.7, < 10.5.0'
patched:
  - dhcpcd 10.5.0
published: '2026-06-23'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T18:06:14.020'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-56116'
references:
  - url: >-
      https://github.com/NetworkConfiguration/dhcpcd/commit/708b4a56bae080a5b18c2e0c4c6fbe103131a2b0
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/dhcpcd-memory-leak-dos-via-ipv6-router-advertisement-handling
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00288
epssPercentile: 0.19562
ingestedAt: '2026-10-08T18:58:11.292Z'
---

## Overview

dhcpcd through 10.3.2, fixed in commit 708b4a5, contains a memory leak vulnerability in the IPv6 Router Advertisement route information handling that allows an unauthenticated same-link attacker to cause denial of service by sending crafted Router Advertisements. Attackers can repeatedly send Router Advertisements containing Route Information options with a lifetime of zero, triggering unfreed allocations in routeinfo_findalloc() that cause linear memory exhaustion and eventual daemon crash.

## Affected

- `dhcpcd >= 10.0.7, < 10.5.0`

## Remediation

Upgrade past the affected range:

- `dhcpcd 10.5.0`