Vulnerability · Published Mar 31, 2026 · Assigned by INCIBE
CVE-2026-4399Multiple vulnerabilities in 1millionbot Millie chatbot
High 8.7
In plain English
A high-severity security flaw in Millie chat from 1millionbot. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 19% of all known vulnerabilities).
Official description
Prompt injection vulnerability in 1millionbot Millie chatbot that occurs when a user manages to evade chat restrictions using Boolean prompt injection techniques (formulating a question in such a way that, upon receiving an affirmative response ('true'), the model executes the injected instruction), causing it to return prohibited information and information outside its intended context. Successful exploitation of this vulnerability could allow a malicious remote attacker to abuse the service for purposes other than those originally intended, or even execute out-of-context tasks using 1millionbot's resources and/or OpenAI's API key. This allows the attacker to evade the containment mechanisms implemented during LLM model training and obtain responses or chat behaviors that were originally restricted.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| 1millionbot | Millie chat | 3.6.0 |
Weakness: CWE-1427 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N