Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| 1Millionbot | Millie Chatbot | < 3.6.0 |
Related Weaknesses (CWE)
References
- https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-1milThird Party Advisory
FAQ
What is CVE-2026-4399?
CVE-2026-4399 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 ...
How severe is CVE-2026-4399?
CVE-2026-4399 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-4399?
Check the references section above for vendor advisories and patch information. Affected products include: 1Millionbot Millie Chatbot.