{"uuid": "1fdee702-388d-47cb-9354-866f414e3bab", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "GHSA-xhcr-cqfr-m3hv", "type": "seen", "source": "https://gist.github.com/alon710/e4526779d0dd30df21e6558b32894929", "content": "# GHSA-XHCR-CQFR-M3HV: GHSA-XHCR-CQFR-M3HV: Remote Code Execution via Insecure HTTP MCP Server Registry in atomic-agents-stack\n\n> **CVSS Score:** 8.7\n> **Published:** 2026-08-17\n> **Full Report:** https://cvereports.com/reports/GHSA-XHCR-CQFR-M3HV\n\n## Summary\nA critical vulnerability exists in the atomic-agents-stack package up to version 1.0.0. The HTTP Model Context Protocol (MCP) server-registry backend factory retrieves catalog metadata over cleartext HTTP by default. Because these catalogs define execution parameters ('command' and 'args') for local stdio subprocesses, a network-positioned attacker can intercept the cleartext traffic and inject arbitrary commands. This results in arbitrary remote code execution on the agent host system without requiring user interaction.\n\n## TL;DR\nUnencrypted HTTP retrieval of Model Context Protocol catalogs allows Man-in-the-Middle attackers to hijack command execution payloads, resulting in arbitrary code execution on the host system.\n\n## Technical Details\n\n- **CWE ID**: CWE-319, CWE-494\n- **Attack Vector**: Network (MITM)\n- **CVSS v4.0**: 8.7\n- **Impact**: Remote Code Execution (RCE)\n- **Exploit Status**: None Documented\n\n## Affected Systems\n\n- atomic-agents-stack (pip package)\n- **atomic-agents-stack**: <= 1.0.0 (Fixed in: `1.1.0`)\n\n## Mitigation\n\n- Upgrade to atomic-agents-stack version 1.1.0 or newer\n- Implement validation policy callbacks via mcp_allow_fn\n- Enforce transport-layer encryption (HTTPS) for all registries\n\n**Remediation Steps:**\n1. Modify pyproject.toml or requirements.txt to specify atomic-agents-stack>=1.1.0\n2. Deploy the updated application to production environments\n3. Audit all registry configuration endpoints and migrate http:// URLs to https://\n\n## References\n\n- [GitHub Security Advisory](https://github.com/advisories/GHSA-XHCR-CQFR-M3HV)\n- [Repository Security Advisory](https://github.com/dep0we/atomic-agents-stack/security/advisories/GHSA-xhcr-cqfr-m3hv)\n- [Release Notes](https://github.com/dep0we/atomic-agents-stack/releases#release-v1.1.0)\n\n\n---\n*Generated by [CVEReports](https://cvereports.com/reports/GHSA-XHCR-CQFR-M3HV) - Automated Vulnerability Intelligence*", "creation_timestamp": "2026-08-18T11:34:49.849524Z"}