CVE-2026-56114
dhcpcd Stack Out-of-Bounds Write in dhcp6_makemessage()
Description
dhcpcd through 10.3.2, fixed in commit 2f00c7b, contains a one-byte stack out-of-bounds write vulnerability in dhcp6_makemessage() in src/dhcp6.c that allows unauthenticated same-link attackers to write beyond a fixed local buffer by serializing an oversized RFC6603 OPTION_PD_EXCLUDE option body. Attackers can send a crafted DHCPv6 ADVERTISE message containing an IA_PD IAPREFIX /0 with a valid OPTION_PD_EXCLUDE using an exclude prefix length of /121 through /128 to trigger the out-of-bounds write and potentially corrupt adjacent stack memory.
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 commit 2f00c7b.
- Apply the vendor-supplied patch.
- Review the changes in src/dhcp6.c.
- Test the system for stability after patching.
Public PoC/Exploit Available at Github
CVE-2026-56114 has a 2 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-2026-56114.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-56114 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-2026-56114
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).
DSA and DLA for Debian last 14 days
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The following list is the news that have been mention
CVE-2026-56114 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-56114 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': '2f00c7bfc408b6582d331932dfa47829c4819029', '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': '2f00c7bfc408b6582d331932dfa47829c4819029', '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:A/AC:L/PR:N/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/2f00c7bfc408b6582d331932dfa47829c4819029 Types: Patch Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/dhcpcd-stack-out-of-bounds-write-in-dhcp6-makemessage 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-2026-56114', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-24T14:02:46.769704Z'} -
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': '2f00c7bfc408b6582d331932dfa47829c4819029', 'versionType': 'git'}], 'defaultStatus': 'affected'}] Added Description dhcpcd through 10.3.2, fixed in commit 2f00c7b, contains a one-byte stack out-of-bounds write vulnerability in dhcp6_makemessage() in src/dhcp6.c that allows unauthenticated same-link attackers to write beyond a fixed local buffer by serializing an oversized RFC6603 OPTION_PD_EXCLUDE option body. Attackers can send a crafted DHCPv6 ADVERTISE message containing an IA_PD IAPREFIX /0 with a valid OPTION_PD_EXCLUDE using an exclude prefix length of /121 through /128 to trigger the out-of-bounds write and potentially corrupt adjacent stack memory. Added CVSS V4.0 AV:A/AC:L/AT:P/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:H/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-787 Added Reference https://github.com/NetworkConfiguration/dhcpcd/commit/2f00c7bfc408b6582d331932dfa47829c4819029 Added Reference https://www.vulncheck.com/advisories/dhcpcd-stack-out-of-bounds-write-in-dhcp6-makemessage