Vulnerability · Published Oct 23, 2026 · Assigned by GitHub_M
CVE-2026-115477obsidian-tc: Declined human-in-the-loop confirmations can permit destructive calls over HTTP
High 7.1
In plain English
A high-severity incorrect authorization in obsidian-tc from The-40-Thieves. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | obsidian-tc | 1.31.4 | GHSA-737x-cwfr-5vvc |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| The-40-Thieves | obsidian-tc | >= 1.13.0, < 1.31.4 |
Weakness: CWE-285, CWE-863 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N
References
- https://github.com/The-40-Thieves/obsidian-tc/security/advisories/GHSA-737x-cwfr-5vvc x_refsource_CONFIRM
- https://github.com/The-40-Thieves/obsidian-tc/issues/967 x_refsource_MISC
- https://github.com/The-40-Thieves/obsidian-tc/pull/969 x_refsource_MISC
- https://github.com/The-40-Thieves/obsidian-tc/commit/101c91c656e2c2b88bcf3696a5da035f8c032c71 x_refsource_MISC
- https://github.com/The-40-Thieves/obsidian-tc/blob/v1.31.4/CHANGELOG.md x_refsource_MISC
- https://github.com/The-40-Thieves/obsidian-tc/releases/tag/v1.31.4 x_refsource_MISC