
Phillip Shoemaker (@pbsIdentity) on X
Social thread reacting to a newly disclosed high-severity OAuth vulnerability in the Model Context Protocol Python SDK, where a malicious MCP server could manipulate the authorization flow and steal credentials used by an agent. The author uses it to argue that delegated agent authority needs provenance (who granted it, to which agent, for which service and resource, whether it is transferable or replayable, and when it expires) and that machine-to-machine trust must be auditable by humans. Gives no CVE ID or technical exploit detail.
TL;DR Thread on the MCP Python SDK OAuth flaw (malicious server can steal agent credentials) arguing agent delegated authority needs auditable provenance.
Technologies named here
Techniques named here
- Credential replay / transfer of delegated authority
- Confused deputy
Related in AI Security
