CVE-2026-77366

obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian vaults. Prior to 1.3.1, tool dispatch does not compare the caller-controlled input.vault value with the vault bound to the caller, the JSON Web Token (JWT) has no vault claim, and the folder access-control list is shared globally. Any valid token can therefore select another configured vault and read, write, or delete its contents through affected tools. Version 1.3.1 fixes the vulnerability by binding tokens and request context to a vault and rejecting mismatched input.vault values before scope checks.

obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian vaults. Prior to 1.3.1, tool dispatch does not compare the caller-controlled input.vault value with the vault bound to the caller, the JSON Web Token (JWT) has no vault claim, and the folder access-control list is shared globally. Any valid token can therefore select another configured vault and read, write, or delete its contents through affected tools. Version 1.3.1 fixes the vulnerability by binding tokens and request context to a vault and rejecting mismatched input.vault values before scope checks.

Impact

Tool dispatch did not check the caller-supplied input.vault against the caller's bound vault (ctx.vaultId); the folder ACL was a single global instance and the JWT carried no vault claim. As a result, any valid token could read, write, or delete any configured vault by passing input.vault, defeating multi-tenant isolation across ~90 tool sites. (resources/read was the only surface that already guarded this.)

Patches

Fixed in 1.3.1 (the fix was developed on the v1.3.0 tag, which never published to npm; 1.3.1 is the first published release with the fix). Upgrade to >= 1.3.1.

Workarounds

Run a single vault per server process, or isolate each tenant on a separate process/credential.

Fix

A central input.vault === ctx.vaultId guard was added in dispatch before the scope check.

obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian vaults. Prior to 1.3.1, tool dispatch does not compare the caller-controlled input.vault value with the vault bound to the caller, the JSON Web Token (JWT) has no vault claim, and the folder access-control list is shared globally. Any valid token can therefore select another configured vault and read, write, or delete its contents through affected tools. Version 1.3.1 fixes the vulnerability by binding tokens and request context to a vault and rejecting mismatched input.vault values before scope checks.

obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian vaults. Prior to 1.3.1, tool dispatch does not compare the caller-controlled input.vault value with the vault bound to the caller, the JSON Web Token (JWT) has no vault claim, and the folder access-control list is shared globally. Any valid token can therefore select another configured vault and read, write, or delete its contents through affected tools. Version 1.3.1 fixes the vulnerability by binding tokens and request context to a vault and rejecting mismatched input.vault values before scope checks.

Impact

Tool dispatch did not check the caller-supplied input.vault against the caller's bound vault (ctx.vaultId); the folder ACL was a single global instance and the JWT carried no vault claim. As a result, any valid token could read, write, or delete any configured vault by passing input.vault, defeating multi-tenant isolation across ~90 tool sites. (resources/read was the only surface that already guarded this.)

Patches

Fixed in 1.3.1 (the fix was developed on the v1.3.0 tag, which never published to npm; 1.3.1 is the first published release with the fix). Upgrade to >= 1.3.1.

Workarounds

Run a single vault per server process, or isolate each tenant on a separate process/credential.

Fix

A central input.vault === ctx.vaultId guard was added in dispatch before the scope check.