# CVE-2021-26264: Emerson DeltaV Missing Authentication for Critical Function

> Attackers can send crafted scripts to restart DeltaV DCS controllers, causing denial of service due to missing authentication.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H`)
- **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:** 28 Jan 2022
- **Updated:** 17 Apr 2025
- **Also known as:** GHSA-x46h-6fmr-m5fr

## What is CVE-2021-26264?

CVE-2021-26264 is a medium-severity missing authorization vulnerability in n/a, published on 28 Jan 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A specially crafted script could cause the DeltaV Distributed Control System Controllers (All Versions) to restart and cause a denial-of-service condition.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2021-26264?

It affects 2 products.


Products: Emerson Deltav Distributed Control System, Emerson Deltav Workstation.

## How do I fix CVE-2021-26264?

No fix has been published for CVE-2021-26264 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-26264 being exploited?

There is no known exploitation of CVE-2021-26264 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2022-29957](https://insights.sbomify.com/CVE-2022-29957/): Missing authorization in n/a (high 7.8)
- [CVE-2022-29965](https://insights.sbomify.com/CVE-2022-29965/): Weak cryptography in n/a (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-26264 and fix it if it is affected.

What it is: CVE-2021-26264 is a medium-severity missing authorization vulnerability in n/a, published on 28 Jan 2022. 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-2021-26264 in the wild and no public exploit code.

Affected product: n/a. 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-2021-26264/ (Markdown: https://insights.sbomify.com/CVE-2021-26264/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-26264
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-26264
- OSV: https://osv.dev/vulnerability/CVE-2021-26264

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-26264/
Summaries are generated and may contain mistakes; the official description above is the record.