CVE-2026-77363

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.

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

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