The vulnerability resides in the file upload endpoint of Langchain‑Chatchat, allowing an attacker to supply a crafted filename that triggers a time‑of‑check to time‑of‑use race condition. This race can overwrite or replace files on the host, potentially enabling persistence of malicious code or destruction of critical data. The weakness is a classic race condition (CWE‑362 and CWE‑367). Because the exploit requires local network access and a high level of technical skill, it is rated low on overall impact.

The affected product is chatchat‑space Langchain‑Chatchat version 0.3.1.3 and all earlier releases. Users deploying the openAI‑compatible file upload API are exposed.

The CVSS score of 2.1 reflects a low severity. EPSS is not available and the vulnerability is not listed in the CISA KEV catalog, indicating limited threat intelligence. However, the attack vector is internal, requiring access to the local network. The exploitation complexity is high and hard to execute, so while the risk of exploitation is low, the potential damage of a successful attack is significant.