# CVE-2026-56117: dhcpcd Heap Use-After-Free via Control Socket Handling

> Local attackers can trigger a use-after-free in dhcpcd control socket handling when privilege separation is disabled, potentially leading to code execution or privilege escalation.

- **Severity:** Medium 5.7 (`CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 23 Jun 2026
- **Updated:** 28 Jul 2026
- **Also known as:** ALPINE-CVE-2026-56117, AZL-90222, BELL-CVE-2026-56117, DEBIAN-CVE-2026-56117, GHSA-p284-r695-7gxf, UBUNTU-CVE-2026-56117

## What is CVE-2026-56117?

CVE-2026-56117 is a medium-severity use after free vulnerability in NetworkConfiguration dhcpcd, published on 23 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-56117?

It affects 1 product.


Products: Dhcpcd Project Dhcpcd.

## How do I fix CVE-2026-56117?

Apply the vendor's patch.

## Is CVE-2026-56117 being exploited?

There is no known exploitation of CVE-2026-56117 in the wild and no public exploit code.

## Other vulnerabilities in NetworkConfiguration dhcpcd

- [CVE-2019-11577](https://insights.sbomify.com/CVE-2019-11577/): Memory corruption in n/a (critical 9.8)
- [CVE-2016-1503](https://insights.sbomify.com/CVE-2016-1503/): Memory corruption in n/a (critical 9.8)
- [CVE-2016-1504](https://insights.sbomify.com/CVE-2016-1504/): dhcpcd before 6.10.0 allows remote attackers to cause a denial of service (invalid read and crash) via vectors related to the option length. (high 7.5)
- [CVE-2026-56116](https://insights.sbomify.com/CVE-2026-56116/): dhcpcd Memory Leak DoS via IPv6 Router Advertisement Handling (high 7.1)
- [CVE-2014-7912](https://insights.sbomify.com/CVE-2014-7912/): Memory corruption in n/a (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-56117 and fix it if it is affected.

What it is: CVE-2026-56117 is a medium-severity use after free vulnerability in NetworkConfiguration dhcpcd, published on 23 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-56117 in the wild and no public exploit code.

Affected product: NetworkConfiguration dhcpcd. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-56117/ (Markdown: https://insights.sbomify.com/CVE-2026-56117/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-56117
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-56117
- OSV: https://osv.dev/vulnerability/CVE-2026-56117

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-56117/
Summaries are generated and may contain mistakes; the official description above is the record.