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TI-2026-56891 Aliases CVE-2026-82533GHSA-8m2g-8cgm-3vcp

DeepSeek Harness < 0.1.2-alpha.1 Authentication Bypass via Host Header Spoofing

Priority MEDIUM 45CWE-807Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.

Summary

DeepSeek Harness before 0.1.2-alpha.1 contains an authentication bypass vulnerability that grants unauthenticated access to its local HTTP agent-control API by accepting a client-supplied loopback Host header in place of validating the actual TCP connection origin. On the default configuration, a confined tool-executed process can reach the loopback API without any port exposure and use it to escape its own OS sandbox, escalate to unconfined execution, and disable the approval prompt. When the port is externally reachable via tunnel, SSH forward, or reverse proxy, a remote attacker can exploit the same flaw to create sessions, execute arbitrary commands, and exfiltrate stored conversation transcripts without credentials.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01238 69th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA
Fix Fixed DeepSeek Harness (DeepSeek): 0.1.2-alpha.1@deepseek-ai/dsh-client-connection (npm): 0.1.2-alpha.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
DeepSeekDeepSeek Harnessbefore 0.1.2-alpha.10.1.2-alpha.1Patch availableCNA
—@deepseek-ai/dsh-client-connection (npm)before 0.1.2-alpha.10.1.2-alpha.1Patch availableGHSA-8m2g-8cgm-3vcp
  • DeepSeek Harness VendorDeepSeek Affected before 0.1.2-alpha.1 Fixed in 0.1.2-alpha.1 Patch available CNA
  • @deepseek-ai/dsh-client-connection (npm) Vendor— Affected before 0.1.2-alpha.1 Fixed in 0.1.2-alpha.1 Patch available GHSA-8m2g-8cgm-3vcp

Remediation

  • Fix · CNA DeepSeek Harness (DeepSeek) Fixed in 0.1.2-alpha.1
  • Fix · GHSA-8m2g-8cgm-3vcp @deepseek-ai/dsh-client-connection (npm) Fixed in 0.1.2-alpha.1 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-82533
  2. 2026-10-03 Alias added: GHSA-8m2g-8cgm-3vcp
  3. 2026-10-07 Fix available: npm/@deepseek-ai/[email protected] · GHSA-8m2g-8cgm-3vcp
  4. 2026-10-07 CVSS score added · GHSA-8m2g-8cgm-3vcp
  5. 2026-10-07 Weakness changed · GHSA-8m2g-8cgm-3vcp
  6. 2026-10-07 5 new references · GHSA-8m2g-8cgm-3vcp

References

Exploit 1

Patch 1

Advisory 1

Other 3

  • TI-2025-19267 DeepSeek R1 through V3.1 allows XSS, as demonstrated by JavaScript execution in the… CVSS 3.1HIGH 8.8
  • TI-2026-80466 Access control flaw in DeepSeek sandbox createContext CVSS 4.0MEDIUM 5.3
  • TI-2026-65141 DeepSeek deepseek-harness Bundle Patch profile.ts loadProfile path traversal CVSS 4.0LOW 2.3
  • TI-2026-80467 Improper authorization in DeepSeek browser authentication CVSS 4.0MEDIUM 6.9
  • TI-2025-39472 DeepSeek V3.2 has a Cross Site Scripting (XSS) vulnerability, which allows JavaScript… CVSS 3.1MEDIUM 6.1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences