CVE-2026-4399

HIGH

Multiple vulnerabilities in 1millionbot Millie chatbot

Title source: cna
STIX 2.1

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.

Scores

CVSS v3 7.5
EPSS 0.0005
EPSS Percentile 16.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-77
Status published
Products (2)
1millionbot/Millie chat 3.6.0
1millionbot/millie_chatbot < 3.6.0
Published Mar 31, 2026
Tracked Since Mar 31, 2026