Vulnerability · Published Jul 9, 2026 · Assigned by GitHub_M
CVE-2026-55604@arikusi/deepseek-mcp-server has an Authorization Bypass Through User-Controlled Key
High 8.6
In plain English
A high-severity authorization bypass via user-controlled key in deepseek-mcp-server from arikusi. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
DeepSeek MCP Server is an MCP server for DeepSeek V4. Starting in version 1.4.2 and prior to version 1.7.0, the process-global `SessionStore` accepts caller-supplied `session_id` values without binding them to any authenticated principal or transport session. An attacker can enumerate active session IDs via `deepseek_sessions`, then reuse a victim-controlled `session_id` in `deepseek_chat` to retrieve and continue the victim's conversation context. Version 1.7.0 contains a patch.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @arikusi/deepseek-mcp-server | 1.7.0 | GHSA-fh3r-g96v-f578 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| arikusi | deepseek-mcp-server | >= 1.4.2, < 1.7.0 |
Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L