CVE-2026-105797
highSimpleChat is a secure AI conversation application with personal and group workspaces for document-grounded interactions.
SimpleChat is a secure AI conversation application with personal and group workspaces for document-grounded interactions. In versions 0.261.003 and 0.261.027, an authorization ordering flaw in POST /api/user/plugins allows an authenticated low-privileged user to omit the top-level MCP type so that _reject_non_admin_mcp_stdio skips inspection before the type is restored from metadata. The stored personal action can then reach McpPluginFactory.create_connector, and MCPStdioPlugin.connect starts the attacker-selected operating-system process under the application service identity when the action tool is invoked. Exploitation requires personal plugins to be enabled and governance to permit MCP actions, and it can expose or modify secrets and data available to the service or disrupt the service. This issue is fixed in version 0.261.031.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/microsoft/simplechat/commit/73ff7d6998dc4827a0f6ba002386275a7c1ec804 security-advisories@github.com
- https://github.com/microsoft/simplechat/security/advisories/GHSA-h4mw-qw8m-5x4j security-advisories@github.com
- https://github.com/microsoft/simplechat/security/advisories/GHSA-h4mw-qw8m-5x4j 134c704f-9b21-4f2e-91b3-4a467353bcc0
