CVE-2026-4399Network attack vector

Restricted output disclosure via Boolean prompt injection

Published Mar 31, 2026 · Updated Mar 31, 2026

Prompt injection in 1MillionBot Millie Platform 3.6.0 allows remote attackers to obtain restricted responses through crafted chat prompts. Boolean prompts make an affirmative model response trigger an injected instruction, bypassing the chatbot's containment rules. No authentication or user interaction is required; impact is bounded to prohibited information, out-of-context behavior, and abuse of service resources.

CVSS severity8.7
High
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Prompt injection in 1MillionBot Millie Platform 3.6.0 allows remote attackers to obtain restricted responses through crafted chat prompts. Boolean prompts make an affirmative model response trigger an injected instruction, bypassing the chatbot's containment rules. No authentication or user interaction is required; impact is bounded to prohibited information, out-of-context behavior, and abuse of service resources.

The record

CVE
CVE-2026-4399
Published
Mar 31, 2026
Updated
Mar 31, 2026
Vendor
1MillionBot
Product
Millie Platform
Classifications
CWE-77, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 31, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 31, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.6.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

1MillionBot · Millie Platformversion=3.6.0

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
8.7Spanish National Cybersecurity Institute, S.A. (INCIBE)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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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