CVE-2026-49291 mcp-memory-service: OAuth read-only clients can write and delete memories through MCP tools/call
Read-only OAuth clients can modify or delete memories via MCP tools due to missing authorization checks on the JSON-RPC endpoint.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-49291?
CVE-2026-49291 is a high-severity missing authorization vulnerability in doobidoo mcp-memory-service, published on 19 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
mcp-memory-service is a semantic memory layer for AI applications. Prior to version 10.65.3, the HTTP MCP JSON-RPC endpoint at `/mcp` requires only OAuth `read` scope for all requests, then dispatches `tools/call` directly to handlers that include mutating tools. A read-only OAuth client can call `store_memory` and `delete_memory` through MCP even though the corresponding REST endpoints require `write` scope. Version 10.65.3 patches the issue.
Weakness: CWE-862
Which versions are affected by CVE-2026-49291?
3 open source packages ship an affected version, including mcp-memory-service.
| Package | Affected | Fixed in |
|---|---|---|
mcp-memory-service PyPI | All versions | 10.65.3 |
mcp-memory-service PyPI | All versions | 10.65.3 |
mcp-memory-service PyPI | All versions | 10.65.3 |
How do I fix CVE-2026-49291?
Upgrade mcp-memory-service to 10.65.3 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-49291 being exploited?
There is no known exploitation of CVE-2026-49291 in the wild and no public exploit code.
Sources
Also known as GHSA-2r68-g678-7qr3, PYSEC-2026-2622.