# CVE-2026-33873: Langflow has Authenticated Code Execution in Agentic Assistant Validation

> Authenticated attackers can execute arbitrary Python code on the server by influencing LLM output in the Agentic Assistant validation phase.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Mar 2026
- **Updated:** 2 Apr 2026
- **Also known as:** ECHO-e568-958c-ec51, GHSA-v8hw-mh8c-jxfc, PYSEC-2026-82

## What is CVE-2026-33873?

CVE-2026-33873 is a critical code injection vulnerability in Langflow Langflow, published on 27 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.9.0, the Agentic Assistant feature in Langflow executes LLM-generated Python code during its validation phase. Although this phase appears intended to validate generated component code, the implementation reaches dynamic execution sinks and instantiates the generated class server-side. In deployments where an attacker can access the Agentic Assistant feature and influence the model output, this can result in arbitrary server-side Python execution. Version 1.9.0 fixes the issue.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-33873?

3 open source packages ship an affected version, including langflow. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `langflow` | PyPI | All versions | 1.9.0 |
| `langflow` | PyPI | All versions | 1.9.0 |
| `langflow` | PyPI | All versions | 1.9.0 |

Products: Langflow Langflow.

## How do I fix CVE-2026-33873?

Upgrade langflow to 1.9.0 or later.

## Is CVE-2026-33873 being exploited?

There is no known exploitation of CVE-2026-33873 in the wild and no public exploit code.

## Other vulnerabilities in Langflow Langflow

- [CVE-2026-9198](https://insights.sbomify.com/CVE-2026-9198/): IBM Langflow Code Injection (critical 9.8, exploited in the wild)
- [CVE-2026-0770](https://insights.sbomify.com/CVE-2026-0770/): Langflow Inclusion of Functionality from Untrusted Control Sphere (critical 9.8, exploited in the wild)
- [CVE-2025-3248](https://insights.sbomify.com/CVE-2025-3248/): Langflow Missing Authentication (critical 9.8, exploited in the wild)
- [CVE-2025-34291](https://insights.sbomify.com/CVE-2025-34291/): Langflow Origin Validation Error (critical 9.4, exploited in the wild)
- [CVE-2026-33017](https://insights.sbomify.com/CVE-2026-33017/): Langflow Code Injection (critical 9.3, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33873 and fix it if it is affected.

What it is: CVE-2026-33873 is a critical code injection vulnerability in Langflow Langflow, published on 27 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-33873 in the wild and no public exploit code.

Affected packages and fixed versions:
- langflow (PyPI): affected all versions; fixed in 1.9.0
- langflow (PyPI): affected all versions; fixed in 1.9.0
- langflow (PyPI): affected all versions; fixed in 1.9.0

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-2026-33873/ (Markdown: https://insights.sbomify.com/CVE-2026-33873/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33873
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33873
- OSV: https://osv.dev/vulnerability/CVE-2026-33873

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33873/
Summaries are generated and may contain mistakes; the official description above is the record.