CVE-2026-115477 — The-40-Thieves

obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian vaults. From 1.13.0 until 1.31.4, on a Streamable HTTP deployment with auth.jwtSecret configured and a 2026-07-28-era client declaring elicitation.form support, a dispatch-gated tool call offered an inputRequired confirmation could still complete after the human declined or cancelled, or the elicitation response was omitted or malformed, provided the client echoed the validly bound requestState on resubmission. The server trusted an authentic, call-bound state as proof of approval even though that state was minted before the elicitation/create leg was asked and proved only that the resubmission belonged to the same call. A client behaving incorrectly or under an attacker's control could therefore execute dispatch-gated destructive vault operations without the human's approval, while still requiring the caller's ordinary tool permissions. Only tools marked destructive: true or requiring a scope with a human-in-the-loop floor were reachable through this bypass. The sixteen handler-side conditionally gated tools, including write_note overwrite and move_note, did not read elicitation state on the modern wire and let neither approval nor decline through that path. Affected deployments using stdio or leaving auth.jwtSecret unset instead used the CLI elicit_token fallback and did not offer this requestState round trip. The fix does not prevent a malicious client from reporting a fabricated approval, because the server cannot verify that the client displayed the form or that a human saw it. This issue is fixed in version 1.31.4.