obsidian-tc, a Model Context Protocol server for Obsidian vaults, had an ACL flaw before release 1.3.1. The file‑reading logic used a lexical vault‑relative path for access checks while containment tests used the resolved real path. A symlink placed inside a vault directory that matched an allowed glob could point to a folder for which the ACL denied read access. The mismatch allowed the symlink to bypass the ACL and expose files in the denied folder. The vulnerability does not allow a user to escape the vault root; reading is limited to files reachable via in‑vault symlinks.

The weakness affects all installations of The-40-Thieves:obsidian-tc older than version 1.3.1. Upgrade to v1.3.1 or later, where ACL checks are performed on the resolved vault‑relative path, eliminating the mismatch.

With a CVSS score of 4.7 this issue is considered moderate. The EPSS score is not available, and the vulnerability is not listed in CISA's KEV catalog, suggesting a lower likelihood of mass exploitation at present. Attackers would need to place a symlink inside the vault and target a folder that the ACL restricts; this requires knowledge of the vault layout and the ability to modify vault contents. While it does not grant full root or system access, it permits unauthorized reading of otherwise protected data within the vault.