CVE-2026-55605

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 65% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this weekElevated
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.3Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

DeepSeek MCP Server is an MCP server for DeepSeek V4. Starting in version 1.4.2 and prior to version 1.8.0, the self-hosted HTTP transport of @arikusi/deepseek-mcp-server exposes POST /mcp without any authentication: createMcpExpressApp is called without an authProvider and no middleware guards the route, so any network-reachable client can issue an unauthenticated initialize request and obtain a valid MCP session identifier. In reproduced testing against commit 5e1302171e99, an unauthenticated client was able to initialize a session, enumerate tools, and invoke the local deepseek_sessions tool with no credentials. The same unauthenticated session also exposes deepseek_chat, whose handler uses the server-side DEEPSEEK_API_KEY when self-hosted deployments configure one. This issue applies to self-hosted HTTP mode, not the separately documented hosted BYOK endpoint in README.md, which expects an Authorization: Bearer ... header. Upstream self-hosted container assets enable HTTP mode by default (Dockerfile) and publish port 3000 (docker-compose.yml). Version 1.8.0 contains a patch for this issue.

CVSS v3
5.3
EG Score
5.3(medium)
EPSS
34.7%
KEV
Not listed

Published

July 9, 2026

Last Modified

July 10, 2026

Advisory Details (3)

Auto-updated Jul 9, 2026
🔬 Proof of concept available. Patch available. Sources: github_release, github.
github Patch Available🟡 PoC Available

Missing Authentication on Self-Hosted HTTP MCP Endpoint · Advisory · arikusi/deepseek-mcp-server · GitHub

https://github.com/arikusi/deepseek-mcp-server/security/advisories/GHSA-72f3-6w86-7rv3
github_release Patch Available

v1.8.0

Patch available: arikusi/deepseek-mcp-server v1.8.0

https://github.com/arikusi/deepseek-mcp-server/releases/tag/v1.8.0
generic

deepseek-mcp-server/CHANGELOG.md at main · arikusi/deepseek-mcp-server · GitHub

https://github.com/arikusi/deepseek-mcp-server/blob/main/CHANGELOG.md#180---2026-06-14

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 12× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-13 22:31 UTCEPSS rescore
  2. 2026-07-13 12:40 UTCEG score recompute
  3. 2026-07-13 06:13 UTCEPSS rescore
  4. 2026-07-13 06:13 UTCEPSS rescore
  5. 2026-07-12 14:56 UTCEG score recompute
  6. 2026-07-12 05:46 UTCEPSS rescore
  7. 2026-07-11 17:11 UTCEG score recompute
  8. 2026-07-11 08:27 UTCEPSS rescore
  9. 2026-07-11 08:27 UTCEPSS rescore
  10. 2026-07-10 19:26 UTCEG score recompute
  11. 2026-07-09 21:42 UTCEG score recompute
  12. 2026-07-09 21:40 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-55605?
CVE-2026-55605 is a medium vulnerability published on July 9, 2026. DeepSeek MCP Server is an MCP server for DeepSeek V4. Starting in version 1.4.2 and prior to version 1.8.0, the self-hosted HTTP transport of @arikusi/deepseek-mcp-server exposes POST /mcp without any authentication: createMcpExpressApp is called without an authProvider and no middleware guards the…
When was CVE-2026-55605 disclosed?
CVE-2026-55605 was first published in the National Vulnerability Database on July 9, 2026, with the most recent update on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55605 actively exploited?
CVE-2026-55605 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 34.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55605?
CVE-2026-55605 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-55605?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55605, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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