CVE-2026-91921 Cross-Site Scripting (XSS) in 1millionbot’s AI chatbot platform
An attacker can inject malicious scripts into the chat interface via unsanitized Markdown, affecting only the victim's own session.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-91921?
CVE-2026-91921 is a medium-severity cross-site scripting vulnerability in AI Chatbot Platform (SaaS) de 1millionbot., published on 21 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Cross-Site Scripting (XSS) vulnerability due to inadequate input sanitisation in the client-side rendering engine of the 1millionbot AI Chat Platform. An unauthenticated remote user could cause external hyperlinks to be rendered in the web interface by sending messages containing Markdown syntax and certain unsanitised content blocks. The impact is limited to the user’s own interactive session; no compromise of internal infrastructure, access to third-party data or impact on administrative panels has been identified.
Weakness: CWE-79
Which versions are affected by CVE-2026-91921?
How do I fix CVE-2026-91921?
No fix has been published for CVE-2026-91921 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-91921 being exploited?
There is no known exploitation of CVE-2026-91921 in the wild and no public exploit code.
Sources
Also known as GHSA-rf8x-cp2v-q2fg.