# CVE-2026-11834: Unauthenticated Command Injection via DHCP Option Handling in Multiple TP-Link Routers

> Adjacent attackers can execute arbitrary commands with elevated privileges on TP-Link routers during initialization via crafted DHCP responses.

- **Severity:** High 8.7 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Jun 2026
- **Updated:** 26 Jun 2026
- **Also known as:** GHSA-w296-94hj-pfcg

## What is CVE-2026-11834?

CVE-2026-11834 is a high-severity command injection vulnerability in TP Link Systems Inc. Archer C20 v5, published on 22 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A command
injection vulnerability has been identified in the DHCP option processing logic
in multiple TP-Link router models, due to insufficient validation of externally
supplied DHCP option data. An adjacent attacker may exploit this
vulnerability by supplying crafted DHCP responses, potentially resulting in unauthorized
command execution during device initialization or provisioning workflows. This
typically occurs when the device is in a factory-default or unconfigured state.

Successful
exploitation may allow an adjacent, unauthenticated attacker to execute
arbitrary commands with elevated privileges, potentially leading to full
compromise of the affected device and unauthorized administrative control.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-11834?


## How do I fix CVE-2026-11834?

No fix has been published for CVE-2026-11834 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-11834 being exploited?

There is no known exploitation of CVE-2026-11834 in the wild and no public exploit code.

Public exploit code:

- Proof of Concept (PoC) for the TP-Link DHCP Option 66 Unauthenticated RCE (CVE-2026-11834) (github_poc): https://github.com/mattgsys/CVE-2026-11834

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-11834 and fix it if it is affected.

What it is: CVE-2026-11834 is a high-severity command injection vulnerability in TP Link Systems Inc. Archer C20 v5, published on 22 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-2026-11834 in the wild and no public exploit code.

Affected product: TP Link Systems Inc. Archer C20 v5. 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-2026-11834/ (Markdown: https://insights.sbomify.com/CVE-2026-11834/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-11834
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-11834
- OSV: https://osv.dev/vulnerability/CVE-2026-11834

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-11834/
Summaries are generated and may contain mistakes; the official description above is the record.