XSS in Chattermate
CVE-2026-24399
ChatterMate is a no-code AI chatbot agent framework. In versions 1.0.8 and below, the chatbot accepts and executes malicious HTML/JavaScript payloads when supplied as chat input. Specifically, an <iframe> payload containing a javascript: URI can be processed and executed in the browser context. This allows access to sensitive client-side data such as localStorage tokens and cookies, resulting in client-side injection. This issue has been fixed in version 1.0.9.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.3 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.003 (25.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 25.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Chattermate
- Chattermate Chattermate.chat — versions < 1.0.9
Weakness classification (CWE)
References
- github.com/chattermate/chattermate.chat/security/advisories/GHSA-72p3-w95w-q3j4 (Exploit, Vendor Advisory)
- github.com/chattermate/chattermate.chat/commit/ff3398031abb97ae28546eaf993fed36… (Patch)
- github.com/chattermate/chattermate.chat/releases/tag/v1.0.9 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-24399?
- CVE-2026-24399 is a critical-severity vulnerability in Chattermate, classified under Cross-site Scripting. CVSS score: 9.3/10. Published 2026-01-24.
- How severe is CVE-2026-24399?
- Critical severity. CVSS v3 base score is 9.3 out of 10.