Vulnerability in @arikusi/deepseek-mcp-server (CVE-2026-55604)
Summary
Vulnerability in @arikusi/deepseek-mcp-server (CVE-2026-55604). Confidential information can be exposed externally. Exploitable via session_id. Mitigation: upgrade to 1.7.0 or later.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-55604 has been found in @arikusi/deepseek-mcp-server.
Attackers can target a specific entry point like session_id over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.6/10.
What to do: upgrade @arikusi/deepseek-mcp-server to 1.7.0 or later.
If unsure, ask your IT team or search "@arikusi/deepseek-mcp-server CVE-2026-55604" on the vendor's site.
CVE-2026-55604 (@arikusi/deepseek-mcp-server) — CWE-639 / CVSS v3 8.6
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: session_id / SessionStore / deepseek_sessions / deepseek_chat
Patched: 1.7.0 — apply immediately
Workaround: If upgrading is not immediately possible, run in STDIO transport (unset TRANSPORT=http) or stop the HTTP server.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-639) exists in @arikusi/deepseek-mcp-server. Attackers reach the vulnerable code path via session_id without authentication.
Check the vendor advisory for the affected versions of @arikusi/deepseek-mcp-server. Attack surface: session_id / SessionStore / deepseek_sessions / deepseek_chat.
Severity: High (CVSS 8.6/10). Confidential information can be exposed externally.
Update to 1.7.0.
Workaround: If upgrading is not immediately possible, run in STDIO transport (unset TRANSPORT=http) or stop the HTTP server.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r '@arikusi/deepseek-mcp-server' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r '@arikusi/deepseek-mcp-server' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
@arikusi/deepseek-mcp-serverを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
If upgrading is not immediately possible, run in STDIO transport (unset `TRANSPORT=http`) or stop the HTTP server.パッチが適用されるまでの応急処置として、If upgrading is not immediately possible, run in STDIO transport (unset
TRANSPORT=http) or stop the HTTP server. を実施。回避策の副作用 (機能低下) を確認した上で。 -
3Apply patch patch
Upgrade @arikusi/deepseek-mcp-server to 1.7.0ステージング環境で 1.7.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web github.com