CVE-2026-42157: XSS in Flowsint OSINT Graph Tool

Successful exploitation of CVE-2026-42157 could allow an attacker to execute arbitrary JavaScript code within the context of a user's Flowsint session. This could lead to the theft of sensitive information, such as API keys, credentials, or data stored within the Flowsint application. An attacker could also potentially redirect users to malicious websites or deface the Flowsint interface. The impact is amplified if Flowsint is used to analyze sensitive data or if it is integrated with other security tools, as the attacker could gain access to a wider range of systems and information.

1. Published2026-05-12

The primary mitigation for CVE-2026-42157 is to upgrade Flowsint to version 1.2.3 or later, which contains the fix for this vulnerability. If upgrading is not immediately feasible, consider implementing input validation and sanitization on the map node label field to prevent the injection of malicious HTML. While not a complete solution, this can reduce the attack surface. Additionally, monitor Flowsint logs for suspicious activity, such as unusual HTML content in map node labels. After upgrading, confirm the fix by creating a map node with a simple HTML tag (e.g., <script>alert('test')</script>) and verifying that the alert does not execute when the map tab is selected.