# CVE-2026-2155: D-Link DIR-823X Configuration set_dmz sub_4208A0 os command injection

> Remote attackers can execute arbitrary OS commands on D-Link DIR-823X routers via the set_dmz configuration handler.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 8 Feb 2026
- **Updated:** 23 Feb 2026
- **Also known as:** GHSA-gfgw-92mr-c3gr

## What is CVE-2026-2155?

CVE-2026-2155 is a high-severity command injection vulnerability in D-Link DIR-823X, published on 8 Feb 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

A security flaw has been discovered in D-Link DIR-823X 250416. The affected element is the function sub_4208A0 of the file /goform/set_dmz of the component Configuration Handler. The manipulation of the argument dmz_host/dmz_enable results in os command injection. The attack can be executed remotely. The exploit has been released to the public and may be used for attacks.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command), CWE-77 (Improper Neutralization of Special Elements used in a Command)

## Which versions are affected by CVE-2026-2155?

It affects 1 product.


Products: Dlink Dir-823x Firmware.

## How do I fix CVE-2026-2155?

No fix has been published for CVE-2026-2155 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-2155 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-2155 exists.

## Other vulnerabilities in D-Link DIR-823X

- [CVE-2025-29635](https://insights.sbomify.com/CVE-2025-29635/): D-Link DIR-823X Command Injection (high 7.2, exploited in the wild)
- [CVE-2025-29040](https://insights.sbomify.com/CVE-2025-29040/): Command injection in n/a (critical 9.8)
- [CVE-2025-29041](https://insights.sbomify.com/CVE-2025-29041/): Command injection in n/a (critical 9.8)
- [CVE-2025-29042](https://insights.sbomify.com/CVE-2025-29042/): Command injection in n/a (critical 9.8)
- [CVE-2025-29043](https://insights.sbomify.com/CVE-2025-29043/): Command injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-2155 and fix it if it is affected.

What it is: CVE-2026-2155 is a high-severity command injection vulnerability in D-Link DIR-823X, published on 8 Feb 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-2155 exists.

Affected product: D-Link DIR-823X. 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-2026-2155/ (Markdown: https://insights.sbomify.com/CVE-2026-2155/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-2155
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-2155
- OSV: https://osv.dev/vulnerability/CVE-2026-2155

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-2155/
Summaries are generated and may contain mistakes; the official description above is the record.