# CVE-2026-5311: D-Link DNS-1550-04 file_center.cgi Webdav_Access_List access control

> Attackers can bypass access controls in the WebDAV access list function of D-Link NAS devices via the file_center.cgi script.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Apr 2026
- **Updated:** 2 Apr 2026
- **Also known as:** GHSA-8c3r-vjwj-2gvx

## What is CVE-2026-5311?

CVE-2026-5311 is a medium-severity missing authorization vulnerability in Dlink Dns-320 Firmware, published on 1 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A security flaw has been discovered in D-Link DNS-120, DNR-202L, DNS-315L, DNS-320, DNS-320L, DNS-320LW, DNS-321, DNR-322L, DNS-323, DNS-325, DNS-326, DNS-327L, DNR-326, DNS-340L, DNS-343, DNS-345, DNS-726-4, DNS-1100-4, DNS-1200-05 and DNS-1550-04 up to 20260205. Affected is the function Webdav_Access_List of the file /cgi-bin/file_center.cgi. Performing a manipulation of the argument cmd results in improper access controls. It is possible to initiate the attack remotely. The exploit has been released to the public and may be used for attacks.

Weakness: CWE-284 (Improper Access Control), CWE-266 (Incorrect Privilege Assignment)

## Which versions are affected by CVE-2026-5311?

It affects 20 products.


Products: Dlink Dnr-202l Firmware, Dlink Dnr-326 Firmware, Dlink Dns-1100-4 Firmware, Dlink Dns-1200-05 Firmware, Dlink Dns-120 Firmware, Dlink Dns-1550-04 Firmware, Dlink Dns-315l Firmware, Dlink Dns-320 Firmware, Dlink Dns-320l Firmware, Dlink Dns-320lw Firmware, Dlink Dns-321 Firmware, Dlink Dns-322l Firmware, Dlink Dns-323 Firmware, Dlink Dns-325 Firmware, Dlink Dns-326 Firmware, Dlink Dns-327l Firmware, Dlink Dns-340l Firmware, Dlink Dns-343 Firmware, Dlink Dns-345 Firmware, Dlink Dns-726-4 Firmware.

## How do I fix CVE-2026-5311?

No fix has been published for CVE-2026-5311 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-5311 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5311 exists.

## Other vulnerabilities in Dlink Dns-320 Firmware

- [CVE-2024-3272](https://insights.sbomify.com/CVE-2024-3272/): D-Link Multiple NAS Devices Use of Hard-Coded Credentials (critical 9.8, exploited in the wild)
- [CVE-2024-3273](https://insights.sbomify.com/CVE-2024-3273/): D-Link Multiple NAS Devices Command Injection (high 7.3, exploited in the wild)
- [CVE-2026-5211](https://insights.sbomify.com/CVE-2026-5211/): D-Link DNS-1550-04 app_mgr.cgi UPnP_AV_Server_Path_Del stack-based overflow (high 8.7)
- [CVE-2026-5212](https://insights.sbomify.com/CVE-2026-5212/): D-Link DNS-1550-04 webdav_mgr.cgi Webdav_Upload_File stack-based overflow (high 8.7)
- [CVE-2026-5213](https://insights.sbomify.com/CVE-2026-5213/): D-Link DNS-1550-04 account_mgr.cgi cgi_adduser_to_session stack-based overflow (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5311 and fix it if it is affected.

What it is: CVE-2026-5311 is a medium-severity missing authorization vulnerability in Dlink Dns-320 Firmware, published on 1 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5311 exists.

Affected product: Dlink Dns-320 Firmware. 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-2026-5311/ (Markdown: https://insights.sbomify.com/CVE-2026-5311/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5311
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5311
- OSV: https://osv.dev/vulnerability/CVE-2026-5311

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5311/
Summaries are generated and may contain mistakes; the official description above is the record.