GitHub Advisoryadvisory · npm
GHSA-rjxq-qqhf-8hwh OpenClaw: MCP Streamable HTTP redirects could forward configured custom headers to another origin
HIGH
Official page ↗
- Aliases
- CVE-2026-53840
- Ecosystem
- npm
- Packages
- openclaw
- Severity
- High
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
- Weaknesses
- CWE-200
- Reviewed
- 2026-06-17
Affected packages
• npm openclaw: < 2026.5.12 → fixed in 2026.5.12
Description
Summary
OpenClaw supports remote MCP Streamable HTTP servers with operator-configured custom headers. In affected releases, those headers could be forwarded when the MCP endpoint responded with a cross-origin redirect.
This issue is limited to configured MCP Streamable HTTP servers that use custom headers. It does not expose unrelated OpenClaw credentials.
Affected configurations
This affects deployments where an MCP server is configured with:
• `transportType: "streamable-http"`
• sensitive custom headers under `mcp.servers.*.headers`
• an MCP endpoint that is malicious, compromised, or able to redirect to another origin
Impact
Custom MCP headers, such as API keys or tenant-routing headers, could be sent to the redirect target. The exposed credential scope depends on the header the operator configured for that MCP server.
Patched Versions
The first stable patched version is `2026.5.12`.
Mitigations
Upgrade to `[email protected]` or later. Before upgrading, avoid custom MCP headers with servers you do not fully trust, and rotate any MCP-specific credentials that may have been exposed by a redirecting endpoint.
Related
Alias · CVE (1)
- CVE-2026-53840 OpenClaw before 2026.5.12 contains an information disclosure vulnerability in streamable-http MCP servers that forwards operator-configured… vulnerability
Weakness · CWE (1)
- CWE-200 Exposure of Sensitive Information to an Unauthorized Actor weakness