CVE-2026-4399CWE-1427

Multiple vulnerabilities in 1millionbot Millie chatbot

High · published March 31, 2026

CVSS v4.0
8.7
EPSS
0%
Percentile
38.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
8.7 · HIGH
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
EPSS
0.00450 · 38.1th percentile
Weakness
CWE-1427 · Improper Neutralization of Input Used for LLM Prompting
Published
2026-03-31T10:10Z
EPSS history
Timeline
  • 31 MAR 10:10Z
    Multiple vulnerabilities in 1millionbot Millie chatbot
    cvelistv5