# CVE-2026-33587: Remote Code Execution (RCE) via Server-Side Template Injection (SSTI)

> Attackers can execute arbitrary Python code and OS commands via Server-Side Template Injection in user-created transformations.

- **Severity:** Critical 9.2 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/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:** 7 May 2026
- **Updated:** 7 May 2026
- **Also known as:** GHSA-f35w-wx37-26q7, GHSA-jqjr-j3vj-vwq3

## What is CVE-2026-33587?

CVE-2026-33587 is a critical code injection vulnerability in Open Notebook, published on 7 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Lack of user input sanitisation in Open Notebook v1.8.3 allows the application user to execute Python code (and subsequently OS commands) on the docker container via Server-Side Template Injection (SSTI) for user-created transformations.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-33587?

It affects 1 product.


Products: Lfnovo Open-Notebook.

## How do I fix CVE-2026-33587?

No fix has been published for CVE-2026-33587 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-33587 being exploited?

There is no known exploitation of CVE-2026-33587 in the wild and no public exploit code.

## Other vulnerabilities in Open Notebook

- [CVE-2026-28201](https://insights.sbomify.com/CVE-2026-28201/): SurrealDB Injection on Open Notebook (high 8.7)
- [CVE-2026-33589](https://insights.sbomify.com/CVE-2026-33589/): Arbitrary File Read via Local File Inclusion (LFI) (high 8.2)
- [CVE-2026-33588](https://insights.sbomify.com/CVE-2026-33588/): Arbitrary File Write Through Path Traversal (high 7.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33587 and fix it if it is affected.

What it is: CVE-2026-33587 is a critical code injection vulnerability in Open Notebook, published on 7 May 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-2026-33587 in the wild and no public exploit code.

Affected product: Open Notebook. 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-2026-33587/ (Markdown: https://insights.sbomify.com/CVE-2026-33587/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33587
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33587
- OSV: https://osv.dev/vulnerability/CVE-2026-33587

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33587/
Summaries are generated and may contain mistakes; the official description above is the record.