CVE-2026-24399

Deeper analysis

CVE-2026-24399 is a cross-site scripting (XSS) vulnerability, classified under CWE-79, affecting ChatterMate, a no-code AI chatbot agent framework in versions 1.0.8 and below. The flaw occurs when the chatbot processes chat input containing malicious HTML/JavaScript payloads, such as an <iframe> element with a javascript: URI, which is then executed directly in the victim's browser context. This client-side injection enables unauthorized access to sensitive data stored client-side, including localStorage tokens and cookies. The vulnerability carries a CVSS v3.1 base score of 9.3 (AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N), indicating critical severity due to its network accessibility, low complexity, and high impact on confidentiality and integrity with changed scope.

Attackers can exploit this vulnerability remotely without privileges by tricking users into submitting crafted chat inputs to a ChatterMate instance, requiring only user interaction such as pasting or entering the payload. No authentication is needed, making it accessible to any adversary. Successful exploitation grants the attacker the ability to steal sensitive client-side data like authentication tokens and cookies in the browser's context, potentially leading to session hijacking, account takeover, or further phishing attacks leveraging the stolen credentials.

Mitigation is available through upgrading to ChatterMate version 1.0.9, where the issue has been addressed. Official advisories and patches are detailed in the GitHub security advisory (GHSA-72p3-w95w-q3j4), the release notes for v1.0.9, and the fixing commit (ff3398031abb97ae28546eaf993fed3619eaffdd), recommending immediate updates for all affected deployments.

As a framework for no-code AI chatbot agents, this vulnerability highlights risks in client-side processing of user inputs in AI-driven web applications, though no public evidence of real-world exploitation has been reported as of the CVE publication on 2026-01-24.