# MervinPraison PraisonAI cross-origin agent execution in AGUI endpoint

Source: https://junglewise.ai/threats/mervinpraison-praisonai-cross-origin-agent-execution-in-agui-endpoint-09843e16  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-10. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

Severity: high · CVSS 8.1 · Published 2026-04-10

PraisonAI is a framework for building and running AI agents. A security flaw in its web interface allows malicious websites to silently execute commands on a user's local AI server if it is running. This could allow an attacker to steal sensitive files, access environment variables, or perform unauthorized actions with the agent's tools without the user's knowledge.

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** High severity, with a CVSS score of 8.1, published 10 April 2026.

**Which products and versions are affected?** MervinPraison praisonaiagents < 4.5.128.

**Is there a fix for This vulnerability?** A patch was published on 2026-04-09: Version 4.5.128 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is This vulnerability attacked?** It is attacked over the network, in a software library.

**Am I affected?** Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The AGUI endpoint (`POST /agui`) in `praisonaiagents` lacks authentication and implements a hardcoded `Access-Control-Allow-Origin: *` header. Because the underlying Starlette/FastAPI framework parses JSON bodies regardless of the `Content-Type` header, an attacker can use a 'simple request' (e.g., `text/plain`) to bypass CORS preflight checks. This allows a malicious website to send arbitrary prompts to a locally running AGUI server. The wildcard CORS header then permits the attacker's site to read the agent's response, leading to data exfiltration and remote tool execution. The issue is fixed in version 4.5.128.

## Affected products

- MervinPraison praisonaiagents < 4.5.128

## Timeline

- 2026-04-09: patched: Version 4.5.128 released
- 2026-04-10: advisory: GitHub Advisory GHSA-x462-jjpc-q4q4 published

## References

- [https://api.github.com/users/offset](https://api.github.com/users/offset)
- [https://github.com/offset](https://github.com/offset)
- [https://api.github.com/users/offset/gists%7B/gist_id%7D](https://api.github.com/users/offset/gists%7B/gist_id%7D)
- [https://api.github.com/users/offset/repos](https://api.github.com/users/offset/repos)
- [https://avatars.githubusercontent.com/u/114768995?v=4](https://avatars.githubusercontent.com/u/114768995?v=4)
- [https://api.github.com/users/offset/events%7B/privacy%7D](https://api.github.com/users/offset/events%7B/privacy%7D)