# CVE-2023-26482: Scope of workflow operations is not validated in nextcloud server

> Missing scope validation allows users to create admin-only workflows, potentially leading to remote code execution if specific apps are enabled.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 30 Mar 2023
- **Updated:** 11 Feb 2025
- **Also known as:** GHSA-h3c9-cmh8-7qpj

## What is CVE-2023-26482?

CVE-2023-26482 is a critical missing authorization vulnerability in Nextcloud Nextcloud Server, published on 30 Mar 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Nextcloud server is an open source home cloud implementation. In affected versions a missing scope validation allowed users to create workflows which are designed to be only available for administrators. Some workflows are designed to be RCE by invoking defined scripts, in order to generate PDFs, invoking webhooks or running scripts on the server. Due to this combination depending on the available apps the issue can result in a RCE at the end. It is recommended that the Nextcloud Server is upgraded to 24.0.10 or 25.0.4. Users unable to upgrade should disable app `workflow_scripts` and `workflow_pdf_converter` as a mitigation.

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

## Which versions are affected by CVE-2023-26482?

It affects 1 product.


Products: Nextcloud Nextcloud Server.

## How do I fix CVE-2023-26482?

No fix has been published for CVE-2023-26482 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-26482 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-26482 exists.

Public exploit code:

- Nextcloud Workflows Remote Code Execution (metasploit)
- https://github.com/ISabbiI/PoC---CVE-2023-26482-RCE-LAB-Nextcloud (github_poc): https://github.com/ISabbiI/PoC---CVE-2023-26482-RCE-LAB-Nextcloud

## Other vulnerabilities in Nextcloud Nextcloud Server

- [CVE-2021-32802](https://insights.sbomify.com/CVE-2021-32802/): Preview generation used third-party library not suited for user-generated content in Nextcloud server (critical 9.3)
- [CVE-2018-3775](https://insights.sbomify.com/CVE-2018-3775/): Auth bypass in Nextcloud Server (high 8.8)
- [CVE-2023-35172](https://insights.sbomify.com/CVE-2023-35172/): Nextcloud Server password reset endpoint is not brute force protected (high 8.7)
- [CVE-2023-32320](https://insights.sbomify.com/CVE-2023-32320/): Nextcloud Server's brute force protection allows someone to send more requests than intended (high 8.7)
- [CVE-2021-32656](https://insights.sbomify.com/CVE-2021-32656/): Trusted servers exchange can be triggered by attacker (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-26482 and fix it if it is affected.

What it is: CVE-2023-26482 is a critical missing authorization vulnerability in Nextcloud Nextcloud Server, published on 30 Mar 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-26482 exists.

Affected product: Nextcloud Nextcloud Server. 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-2023-26482/ (Markdown: https://insights.sbomify.com/CVE-2023-26482/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-26482
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-26482
- OSV: https://osv.dev/vulnerability/CVE-2023-26482

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-26482/
Summaries are generated and may contain mistakes; the official description above is the record.