CVE-2026-91921Network attack vector

Session-scoped XSS via unsanitized Markdown rendering

Published Sep 21, 2026 · Updated Sep 21, 2026

Cross-site scripting in 1MillionBot Millie Platform allows remote attackers to render external links in their own interactive sessions. The client-side rendering engine inadequately sanitizes Markdown syntax and certain content blocks before rendering them in the web interface. An unauthenticated sender can affect only the sender's session; no third-party data, infrastructure, or administrative panel is exposed.

CVSS severity5.1
Medium
EPSS probability0.60%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in 1MillionBot Millie Platform allows remote attackers to render external links in their own interactive sessions. The client-side rendering engine inadequately sanitizes Markdown syntax and certain content blocks before rendering them in the web interface. An unauthenticated sender can affect only the sender's session; no third-party data, infrastructure, or administrative panel is exposed.

The record

CVE
CVE-2026-91921
Published
Sep 21, 2026
Updated
Sep 21, 2026
Vendor
1MillionBot
Product
Millie Platform
Classifications
CWE-79
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 21, 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=Version prior to CVE publication

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

1MillionBot · Millie Platformversion=Version prior to CVE publication

Published CVSS scores

5.1INCIBECVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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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