# CVE-2026-57206: Microsoft SimpleChat missing authentication in plugin validation endpoints

Source: https://junglewise.ai/threats/cve-2026-57206-microsoft-simplechat-missing-authentication-in-plugin-validation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-16. Updated: 2026-07-16  
License: CC BY 4.0 with a link back

CVE-2026-57206 · Severity: high · CVSS 8.6 · Published 2026-07-16

SimpleChat, an AI conversation platform for document-based collaboration, contained a security flaw where several administrative and plugin management features were accessible without a password. An unauthorized person on the network could potentially view plugin health data, modify global plugin configurations, or tamper with the application's storage state. This could lead to unauthorized changes to how the AI interacts with documents or a disruption of the service.

Technologies: [Microsoft SimpleChat](https://junglewise.ai/threats/technologies/simplechat). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-57206 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-57206 being exploited in the wild.

**How severe is CVE-2026-57206?** High severity, with a CVSS score of 8.6, published 16 July 2026.

**Which products and versions are affected?** Microsoft SimpleChat < 0.241.206.

**Is there a fix for CVE-2026-57206?** A patch was published on 2026-06-25: Version 0.250.001 released (includes fix from 0.241.206) Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-57206 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-57206?** Check whether you run Microsoft SimpleChat at an affected version. 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

SimpleChat versions prior to 0.241.206 fail to enforce runtime authentication and authorization on several API endpoints located in `application/single_app/plugin_validation_endpoint.py`. While these routes were documented with security metadata via `@swagger_route`, they lacked the necessary `@login_required`, `@user_required`, or `@admin_required` decorators required for actual enforcement. An unauthenticated attacker can reach these endpoints over the network to enumerate plugin types, trigger server-side instantiation with malicious manifests, or invoke the 'repair' logic to modify global plugin metadata and persisted storage. The vulnerability is addressed in version 0.241.206 by adding the appropriate runtime decorators to the affected routes.

## Affected products

- Microsoft SimpleChat < 0.241.206

## Timeline

- 2026-06-17: advisory: GitHub Security Advisory GHSA-g6gr-xp46-hrmj published
- 2026-06-25: patched: Version 0.250.001 released (includes fix from 0.241.206)
- 2026-07-16: disclosed: CVE-2026-57206 published to NVD

## References

- [https://github.com/microsoft/simplechat/blob/main/docs/explanation/fixes/PLUGIN_VALIDATION_ROUTE_AUTH_FIX.md](https://github.com/microsoft/simplechat/blob/main/docs/explanation/fixes/PLUGIN_VALIDATION_ROUTE_AUTH_FIX.md)
- [https://github.com/microsoft/simplechat/releases/tag/v0.250.001](https://github.com/microsoft/simplechat/releases/tag/v0.250.001)
- [https://github.com/microsoft/simplechat/security/advisories/GHSA-g6gr-xp46-hrmj](https://github.com/microsoft/simplechat/security/advisories/GHSA-g6gr-xp46-hrmj)

## Related threats

- [SimpleChat stored XSS in group document filename](https://junglewise.ai/threats/cve-2026-105798-simplechat-is-a-secure-ai-conversation-application-with-personal)
- [SimpleChat authorization ordering flaw in MCP plugins](https://junglewise.ai/threats/cve-2026-105797-simplechat-is-a-secure-ai-conversation-application-with-personal)
- [Microsoft SimpleChat IDOR in user profile endpoints](https://junglewise.ai/threats/cve-2026-57205-microsoft-simplechat-idor-in-user-profile-endpoints)