CVE-2026-56116
dhcpcd Memory Leak DoS via IPv6 Router Advertisement Handling
Description
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.
INFO
Published Date :
June 23, 2026, 5:17 p.m.
Last Modified :
Oct. 25, 2026, 11:10 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Apply the patch from commit 708b4a5.
- Update dhcpcd to a version containing the fix.
- Monitor system resources after applying the fix.
Public PoC/Exploit Available at Github
CVE-2026-56116 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-56116.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-56116 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-56116
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-56116 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-56116 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 25, 2026
Action Type Old Value New Value Added Translation Title: dhcpcd de NetworkConfiguration, Description: dhcpcd hasta la versión 10.3.2, corregido en el commit 708b4a5, contiene una vulnerabilidad de fuga de memoria en el manejo de información de ruta de los anuncios de router IPv6 que permite a un atacante no autenticado en el mismo enlace causar una denegación de servicio mediante el envío de anuncios de router manipulados. Los atacantes pueden enviar repetidamente anuncios de router que contienen opciones de Información de Ruta con una vida útil de cero, desencadenando asignaciones no liberadas en routeinfo_findalloc() que causan un agotamiento lineal de la memoria y el eventual fallo del demonio. -
Modified Analysis by [email protected]
Oct. 08, 2026
Action Type Old Value New Value Changed CPE Configuration OR *cpe:2.3:a:dhcpcd_project:dhcpcd:*:*:*:*:*:*:*:* versions up to (including) 10.3.2 OR *cpe:2.3:a:dhcpcd_project:dhcpcd:*:*:*:*:*:*:*:* versions from (including) 10.0.7 up to (excluding) 10.5.0 -
CVE Modified by [email protected]
Jul. 14, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://github.com/NetworkConfiguration/dhcpcd', 'vendor': 'NetworkConfiguration', 'product': 'dhcpcd', 'versions': [{'status': 'affected', 'version': '10.0.7', 'versionType': 'semver', 'lessThanOrEqual': '10.3.2'}, {'status': 'unaffected', 'version': '708b4a56bae080a5b18c2e0c4c6fbe103131a2b0', 'versionType': 'git'}], 'defaultStatus': 'affected'}] [{'repo': 'https://github.com/NetworkConfiguration/dhcpcd', 'vendor': 'NetworkConfiguration', 'product': 'dhcpcd', 'versions': [{'status': 'affected', 'version': '10.0.7', 'versionType': 'semver', 'lessThanOrEqual': '10.3.2'}, {'status': 'unaffected', 'version': '708b4a56bae080a5b18c2e0c4c6fbe103131a2b0', 'versionType': 'git'}], 'packageURL': 'pkg:github/NetworkConfiguration/dhcpcd', 'defaultStatus': 'affected'}] -
CVE Modified by [email protected]
Jul. 01, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://github.com/NetworkConfiguration/dhcpcd', 'vendor': 'NetworkConfiguration', 'product': 'dhcpcd', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '10.3.2'}, {'status': 'unaffected', 'version': '708b4a56bae080a5b18c2e0c4c6fbe103131a2b0', 'versionType': 'git'}], 'defaultStatus': 'affected'}] [{'repo': 'https://github.com/NetworkConfiguration/dhcpcd', 'vendor': 'NetworkConfiguration', 'product': 'dhcpcd', 'versions': [{'status': 'affected', 'version': '10.0.7', 'versionType': 'semver', 'lessThanOrEqual': '10.3.2'}, {'status': 'unaffected', 'version': '708b4a56bae080a5b18c2e0c4c6fbe103131a2b0', 'versionType': 'git'}], 'defaultStatus': 'affected'}] -
Initial Analysis by [email protected]
Jun. 28, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:dhcpcd_project:dhcpcd:*:*:*:*:*:*:*:* versions up to (including) 10.3.2 Added Reference Type VulnCheck: https://github.com/NetworkConfiguration/dhcpcd/commit/708b4a56bae080a5b18c2e0c4c6fbe103131a2b0 Types: Patch Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/dhcpcd-memory-leak-dos-via-ipv6-router-advertisement-handling Types: Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 23, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-56116', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-23T17:00:12.933242Z'} -
New CVE Received by [email protected]
Jun. 23, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/NetworkConfiguration/dhcpcd', 'vendor': 'NetworkConfiguration', 'product': 'dhcpcd', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '10.3.2'}, {'status': 'unaffected', 'version': '708b4a56bae080a5b18c2e0c4c6fbe103131a2b0', 'versionType': 'git'}], 'defaultStatus': 'affected'}] Added Description 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. Added CVSS V4.0 AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-401 Added Reference https://github.com/NetworkConfiguration/dhcpcd/commit/708b4a56bae080a5b18c2e0c4c6fbe103131a2b0 Added Reference https://www.vulncheck.com/advisories/dhcpcd-memory-leak-dos-via-ipv6-router-advertisement-handling