Key points
- Agent Zero Web UI versions prior to 1.15 contain a high-severity vulnerability.
- The flaw allows cross-site scripting via unsanitized chat messages and file uploads.
- A fix is available in version 1.15, which corrects input sanitization processes.
Organizations using Agent Zero Web UI must upgrade to version 1.15 immediately to address a high-severity security flaw. The vulnerability, tracked as CVE-2026-97635, affects all versions of the software released before 1.15. According to the National Vulnerability Database, this issue allows attackers to inject malicious JavaScript code through chat messages or file uploads.
In plain English
The software does not properly clean user input before displaying it. When a user sends a chat message or uploads a file containing hidden JavaScript, the system reproduces that content in the interface. Because the input is not sanitized, the browser executes the script. This happens within the context of the victim’s authenticated session, meaning the script can act with the same permissions as the logged-in user.
The background
The National Vulnerability Database assigns a CVSS score of 8.1 to this issue, classifying it as high severity. The weakness is categorized under CWE-79, which relates to improper neutralization of input during web page generation. The flaw exists specifically in how Agent Zero handles user-provided input in its chat interface and file upload mechanisms prior to the 1.15 release.
What changes now
Version 1.15 of Agent Zero Web UI includes a patch that corrects the input sanitization process. This update ensures that user-provided content in chat messages and file uploads is properly neutralized before being rendered. Administrators should verify their current version and apply the update to prevent potential session hijacking or data theft through executed scripts.
Who needs to act first
Teams should prioritize updating systems that are accessible to external users or untrusted internal networks. Before rolling out the patch, test the update in a non-production environment to ensure compatibility with existing workflows. Back up current configurations and data to allow for quick restoration if issues arise. If immediate updating is impossible, restrict access to the web interface to trusted users only and monitor for suspicious activity.
What to do and how to stay safe: Agent Zero
- Check your current Agent Zero Web UI version and compare it against 1.15.
- Apply the update to version 1.15 once you have verified its stability in testing.
- Monitor server logs for unusual JavaScript execution or unexpected session behavior.
- Review file upload permissions to ensure only authorized users can submit content.
Step-by-step guide: Emergency Patching: How to Fix Critical Flaws Without Breaking Systems
General security guidance from the Patch Review newsroom. It is not confirmed advice from the organisations named in this story.
Frequently asked questions
What is the CVSS score for CVE-2026-97635?
The National Vulnerability Database rates this vulnerability as 8.1, which is considered high severity.
Which versions of Agent Zero are affected?
All versions of Agent Zero Web UI released before version 1.15 are affected by this flaw.
How is the vulnerability exploited?
Attackers can inject JavaScript through chat messages or file uploads, which executes in the victim's session.
