Vulnerability · Published Oct 12, 2026 · Assigned by GitHub_M

CVE-2026-77366obsidian-tc tokens can access arbitrary configured vaults

Critical 9.9

In plain English

A critical-severity authorization bypass via user-controlled key 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 0.3% (higher than 24% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.9Critical

Exploit odds (30 days)0.3%top 76.2% 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, 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	obsidian-tc	1.3.1	GHSA-84c9-qqpq-2pq5

Affected products (as reported)

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

Weakness: CWE-639, CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

References

https://github.com/The-40-Thieves/obsidian-tc/security/advisories/GHSA-84c9-qqpq-2pq5 x_refsource_CONFIRM
https://github.com/The-40-Thieves/obsidian-tc/pull/72 x_refsource_MISC
https://github.com/The-40-Thieves/obsidian-tc/commit/38b4992e87dc2715564236e1a42d005ab05a0194 x_refsource_MISC
https://github.com/The-40-Thieves/obsidian-tc/releases/tag/v1.3.1 x_refsource_MISC