The vulnerability arises from a failure by bridge tools to consistently apply the read access‑control list (ACL) to all returned fields. As a result, authenticated users can invokes the tasks_filter, makemd_query, and list_templates tools and receive data from notes that are outside their read ACL, enabling them to infer or read sensitive content. This is categorized as CWE‑200 (Information Exposure) and CWE‑863 (Access Control Weakness). The impacted data includes group counts, sibling result fields, template paths, and user‑function bodies that are normally protected.

The-40-Thieves:obsidian‑tc, the Model Context Protocol server for Obsidian vaults, is affected. Versions prior to 1.3.1 suffer from the ACL enforcement flaw; version 1.3.1 and later incorporate filtering of path‑attributable fields and apply the read whitelist to list_templates. Any deployment using the bridge tools before the release cannot prevent data leakage through the affected commands.

The CVSS score of 4.3 indicates a low to moderate severity. EPSS is not available and the vulnerability is not listed in CISA KEV, suggesting limited current exploitation activity. The attack surface is restricted to authenticated users with access to the bridge tools, implying that compromise of user credentials is required, but the flaw can still compromise confidential data if credentials are exposed or reused.