CVE-2026-42159 Flowsint: Stored XSS in description of node
A remote attacker can inject malicious HTML into node descriptions, leading to stored XSS when viewed by other users.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-42159?
CVE-2026-42159 is a medium-severity cross-site scripting vulnerability in reconurge flowsint, published on 14 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Flowsint is an open-source OSINT graph exploration tool designed for cybersecurity investigation, transparency, and verification. Prior to 1.2.3, Flowsint allows a user to create investigations, which are used to manage sketches and analyses. Sketches have controllable graphs, which are comprised of nodes and relationships. The sketches contain information on an OSINT target (usernames, websites, etc) within these nodes and relationships. A remote attacker can create a node with a malicious description that contains arbitrary HTML. When the node is selected, it will render the arbitrary HTML, potentially triggering stored XSS. This vulnerability is fixed in 1.2.3.
Weakness: CWE-79
Which versions are affected by CVE-2026-42159?
It affects 1 product.
Products include Flowsint Flowsint.
How do I fix CVE-2026-42159?
No fix has been published for CVE-2026-42159 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-42159 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42159 exists.
Other vulnerabilities in reconurge flowsint
Sources
Also known as GHSA-w233-5mmx-cr7x.