This vulnerability is a type‑confusion flaw in Timescale's pgvectorscale that lets a low‑privileged database user, with CREATE rights on the vectorscale schema, shadow the pgvector vector type or its operators. By pre‑creating shadow objects, an attacker can build and query DiskANN indexes over crafted values, leading to out‑of‑bounds reads and writes. The result may include disclosure of sensitive memory contents, server crashes, or escalation of privileges. The weakness is described by CWE‑843.

The affected product is Timescale pgvectorscale, specifically all releases before 0.9.1 (e.g., 0.9.0). Attackers must have CREATE privileges within the vectorscale schema to exploit the issue.

The CVSS score of 7.7 marks the flaw as high severity, and while EPSS is not available, the lack of immediate exploitation evidence does not diminish the risk. The flaw is not listed in the CISA KEV catalog. An attacker requires only local database access with limited privileges but can leverage the schema’s CREATE permission to manipulate the indexing layer, rendering the attack relatively low effort for an authenticated attacker.