Vulnerability · Published Oct 12, 2026 · Assigned by GitHub_M

CVE-2026-77363obsidian-tc Streamable HTTP transport permits cross-origin loopback vault access

High 8.8

In plain English

A high-severity security flaw in obsidian-tc from The-40-Thieves. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.2%top 95.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	obsidian-tc	1.3.1	GHSA-pqh8-4pj7-32xx

Affected products (as reported)

Vendor	Product	Versions
The-40-Thieves	obsidian-tc	< 1.3.1

Weakness: CWE-346, CWE-1385 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References

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