CVE-2026-77363

HIGH 8.8

obsidian-tc Streamable HTTP transport permits cross-origin loopback vault access

CVSS Score

8.8

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-346 CWE-1385
Vendor	the-40-thieves
Product	obsidian-tc
Published	Oct 12, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

The-40-Thieves / obsidian-tc

< 1.3.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/The-40-Thieves/obsidian-tc/security/advisories/GHSA-pqh8-4pj7-32xx github.com: https://github.com/The-40-Thieves/obsidian-tc/pull/74 github.com: https://github.com/The-40-Thieves/obsidian-tc/commit/6428bfe6fdfd43aa7b4b369be3aecd6a268fb928 github.com: https://github.com/The-40-Thieves/obsidian-tc/releases/tag/v1.3.1