Open WebUI is a self-hosted artificial intelligence platform that can run entirely offline. Before version 0.8.0, the GET /api/v1/memories/ef endpoint is accessible without authentication and invokes an embedding function, allowing any user to request embeddings. If those embeddings are performed against a paid provider, an attacker can trigger direct cost exposure and potentially overwhelm the provider, leading to a denial‑of‑service scenario for the legitimate user base. This weakness is classified as Missing Authorization (CWE‑862).

The vulnerable product is open‑webui:open‑webui. All releases prior to 0.8.0 are affected; the issue was fixed in 0.8.0 and later versions. No other vendors or products are listed.

The CVSS score of 6.5 indicates moderate severity. No EPSS value is available, and the vulnerability is not listed in the CISA KEV catalog. Based on the description, it is inferred that an attacker only needs unauthenticated HTTP access to the vulnerable endpoint; no special privileges or network exploits are required. Consequently, any entity able to reach the service can initiate costly embedding calls, posing a financial risk and a potential denial‑of‑service vector if usage spikes.