CVE-2026-4399: CWE-1427 Improper neutralization of input used for LLM prompting in 1millionbot Millie chat
CVE-2026-4399 is a prompt injection vulnerability in the 1millionbot Millie chatbot version 3. 6. 0. It allows attackers to bypass chat restrictions by crafting inputs that cause the model to execute unintended instructions, potentially revealing prohibited information or performing out-of-context tasks. This vulnerability can lead to abuse of the chatbot service and misuse of associated resources, including OpenAI's API key. The vulnerability has a high severity score of 8. 7 but no known exploits in the wild have been reported. No official patch or remediation guidance is currently available.
AI Analysis
Technical Summary
The vulnerability identified as CVE-2026-4399 in 1millionbot Millie chat version 3.6.0 involves improper neutralization of input used for large language model (LLM) prompting (CWE-1427). Attackers can use Boolean prompt injection techniques to evade chat restrictions, causing the chatbot to execute injected instructions when it receives an affirmative response. This results in the chatbot returning information or performing tasks outside its intended scope, potentially abusing the service and associated resources such as OpenAI's API key. The CVSS 4.0 base score is 8.7, indicating high severity, with network attack vector, low attack complexity, no privileges or user interaction required, and high impact on confidentiality.
Potential Impact
Successful exploitation allows remote attackers to bypass implemented containment mechanisms in the LLM, leading to unauthorized disclosure of restricted information and execution of unintended commands. This could result in misuse of the chatbot service and its resources, including unauthorized use of OpenAI's API key. There are no reports of active exploitation in the wild at this time.
Mitigation Recommendations
No official patch or remediation is currently available for this vulnerability. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is released, users should exercise caution when deploying or exposing the affected version (3.6.0) of 1millionbot Millie chat and monitor vendor communications for updates.
CVE-2026-4399: CWE-1427 Improper neutralization of input used for LLM prompting in 1millionbot Millie chat
Description
CVE-2026-4399 is a prompt injection vulnerability in the 1millionbot Millie chatbot version 3. 6. 0. It allows attackers to bypass chat restrictions by crafting inputs that cause the model to execute unintended instructions, potentially revealing prohibited information or performing out-of-context tasks. This vulnerability can lead to abuse of the chatbot service and misuse of associated resources, including OpenAI's API key. The vulnerability has a high severity score of 8. 7 but no known exploits in the wild have been reported. No official patch or remediation guidance is currently available.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability identified as CVE-2026-4399 in 1millionbot Millie chat version 3.6.0 involves improper neutralization of input used for large language model (LLM) prompting (CWE-1427). Attackers can use Boolean prompt injection techniques to evade chat restrictions, causing the chatbot to execute injected instructions when it receives an affirmative response. This results in the chatbot returning information or performing tasks outside its intended scope, potentially abusing the service and associated resources such as OpenAI's API key. The CVSS 4.0 base score is 8.7, indicating high severity, with network attack vector, low attack complexity, no privileges or user interaction required, and high impact on confidentiality.
Potential Impact
Successful exploitation allows remote attackers to bypass implemented containment mechanisms in the LLM, leading to unauthorized disclosure of restricted information and execution of unintended commands. This could result in misuse of the chatbot service and its resources, including unauthorized use of OpenAI's API key. There are no reports of active exploitation in the wild at this time.
Mitigation Recommendations
No official patch or remediation is currently available for this vulnerability. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is released, users should exercise caution when deploying or exposing the affected version (3.6.0) of 1millionbot Millie chat and monitor vendor communications for updates.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- INCIBE
- Date Reserved
- 2026-03-18T17:18:15.620Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 69cba419e6bfc5ba1d08ffa6
Added to database: 3/31/2026, 10:38:17 AM
Last enriched: 4/7/2026, 10:57:19 AM
Last updated: 5/15/2026, 3:31:13 PM
Views: 92
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