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TI-2026-71220 Aliases CVE-2026-77363GHSA-pqh8-4pj7-32xx

Missing origin checks in obsidian-tc expose local vault to web pages

Priority LOW 39CWE-1385Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-346.

Summary

obsidian-tc before 1.3.1 has a flaw in its Streamable HTTP transport, which does not validate the Host or Origin headers (CWE-346). When the documented loopback configuration sets auth.mode to none, a malicious web page that a user visits can send requests to the local MCP endpoint and gain unrestricted vault access through the http-local caller.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian vaults. Prior to 1.3.1, the Streamable HTTP transport does not validate the Host or Origin header or enable DNS-rebinding protection. When the documented loopback configuration uses auth.mode set to none, a malicious web page can send requests to the local MCP endpoint and receive unrestricted vault access through the http-local caller. Version 1.3.1 fixes the vulnerability by enabling host, origin, and DNS-rebinding validation.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00155 4th percentileScored 2026-11-07
Fix Fixed obsidian-tc (The-40-Thieves): 1.3.1obsidian-tc (npm): 1.3.1

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
The-40-Thievesobsidian-tcbefore 1.3.11.3.1Patch availableCNA
—obsidian-tc (npm)before 1.3.11.3.1Patch availableGHSA-pqh8-4pj7-32xx
  • obsidian-tc VendorThe-40-Thieves Affected before 1.3.1 Fixed in 1.3.1 Patch available CNA
  • obsidian-tc (npm) Vendor— Affected before 1.3.1 Fixed in 1.3.1 Patch available GHSA-pqh8-4pj7-32xx

Remediation

Upgrade the npm package obsidian-tc to version 1.3.1, which enables host, origin, and DNS-rebinding validation. The sources list no fixed version for obsidian-tc.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA obsidian-tc (The-40-Thieves) Fixed in 1.3.1
  • Fix · GHSA-pqh8-4pj7-32xx obsidian-tc (npm) Fixed in 1.3.1 Advisory →

Timeline

  1. 2026-10-12 Threatist record created from CVE-2026-77363
  2. 2026-10-13 Priority changed: MEDIUM → LOW
  3. 2026-10-13 CISA SSVC decision points changed
  4. 2026-10-23 Alias added: GHSA-pqh8-4pj7-32xx
  5. 2026-10-23 Fix available: npm/[email protected] · GHSA-pqh8-4pj7-32xx
  6. 2026-10-23 CVSS score added · GHSA-pqh8-4pj7-32xx
  7. 2026-10-23 Weakness changed · GHSA-pqh8-4pj7-32xx
  8. 2026-10-23 6 new references · GHSA-pqh8-4pj7-32xx

References

Advisory 1

Other 5

  • TI-2026-79945 Declined confirmations in obsidian-tc permit destructive tool calls CVSS 4.0HIGH 7.1
  • TI-2026-71222 Authorization bypass in obsidian-tc lets tokens access other vaults CVSS 3.1CRITICAL 9.9
  • TI-2026-79946 Memory tools in obsidian-tc overwrite unowned notes on disk CVSS 4.0HIGH 7.1
  • TI-2026-71221 Default ACL in obsidian-tc exposes Obsidian control-directory secrets CVSS 3.1MEDIUM 6.5
  • TI-2026-71748 Symlink path mismatch in obsidian-tc bypasses read ACL restrictions CVSS 3.1MEDIUM 4.7
  • TI-2026-71798 Missing read ACL checks in obsidian-tc expose note data CVSS 3.1MEDIUM 4.3

Sources

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