CVE-2026-56117
dhcpcd Heap Use-After-Free via Control Socket Handling
Description
dhcpcd through 10.3.2, fixed in commit 78ea09e, contains a heap use-after-free vulnerability in the control socket handling within src/control.c that allows local unprivileged attackers to trigger memory corruption when privilege separation is disabled. Attackers can connect to the control socket and send a privileged command such as -x, causing control_recvdata() to free the client object while the same READ+HANGUP event subsequently reaches control_hangup() with the stale pointer, resulting in a use-after-free condition exploitable in deployments using --disable-privsep or where privsep initialization has failed with the control socket operating in mode 0666.
INFO
Published Date :
June 23, 2026, 5:17 p.m.
Last Modified :
July 14, 2026, 10:17 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 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update dhcpcd to a version that includes the fix.
- Apply the security patch for control socket handling.
- Ensure privilege separation is enabled and configured.
- Remove the '-x' command if used.
Public PoC/Exploit Available at Github
CVE-2026-56117 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-2026-56117.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-56117 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-2026-56117
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-2026-56117 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-56117 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 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': '0', 'versionType': 'semver', 'lessThanOrEqual': '10.3.2'}, {'status': 'unaffected', 'version': '78ea09ed1633a583dbcde6e7bab9df4639ec8a34', 'versionType': 'git'}], 'defaultStatus': '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': '78ea09ed1633a583dbcde6e7bab9df4639ec8a34', 'versionType': 'git'}], 'packageURL': 'pkg:github/NetworkConfiguration/dhcpcd', 'defaultStatus': 'affected'}] -
Initial Analysis by [email protected]
Jun. 28, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H 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/78ea09ed1633a583dbcde6e7bab9df4639ec8a34 Types: Patch Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/dhcpcd-heap-use-after-free-via-control-socket-handling Types: Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 24, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-56117', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-24T13:43:04.591782Z'} -
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': '78ea09ed1633a583dbcde6e7bab9df4639ec8a34', 'versionType': 'git'}], 'defaultStatus': 'affected'}] Added Description dhcpcd through 10.3.2, fixed in commit 78ea09e, contains a heap use-after-free vulnerability in the control socket handling within src/control.c that allows local unprivileged attackers to trigger memory corruption when privilege separation is disabled. Attackers can connect to the control socket and send a privileged command such as -x, causing control_recvdata() to free the client object while the same READ+HANGUP event subsequently reaches control_hangup() with the stale pointer, resulting in a use-after-free condition exploitable in deployments using --disable-privsep or where privsep initialization has failed with the control socket operating in mode 0666. Added CVSS V4.0 AV:L/AC:L/AT:P/PR:L/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:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-416 Added Reference https://github.com/NetworkConfiguration/dhcpcd/commit/78ea09ed1633a583dbcde6e7bab9df4639ec8a34 Added Reference https://www.vulncheck.com/advisories/dhcpcd-heap-use-after-free-via-control-socket-handling