The vulnerability in mcp-memory-service occurs because all HTTP routes under /api/documents/* are served without authentication, even when the application is configured with an API key or OAuth. An unauthenticated remote attacker can upload arbitrary content into the memory store (write), retrieve stored document content (read), and permanently delete memories belonging to authenticated users (delete). The missing authentication boundary allows attackers to compromise confidentiality, integrity, and availability of the semantic memory layer.

doobidoo mcp-memory-service versions prior to 10.67.1 are affected. The vulnerability applies to all deployments of this service that use the /api/documents/* endpoints without proper authentication enforcement.

The CVSS score of 9.8 reflects a critical level of risk. Because the flaw resides in public HTTP endpoints, an attacker can exploit it remotely from any network where the service is exposed. Although an EPSS score is not available, the lack of authentication makes exploitation straightforward and likely highly valuable to adversaries. The vulnerability is not yet listed in the CISA KEV catalog, but the high CVSS and wide exposure warrant immediate attention.