XSS in Flowsint
CVE-2026-42159
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (19.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 19.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- Flowsint
- Reconurge Flowsint — versions < 1.2.3
Weakness classification (CWE)
References
- github.com/reconurge/flowsint/security/advisories/GHSA-w233-5mmx-cr7x (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-42159?
- CVE-2026-42159 is a medium-severity vulnerability in Flowsint, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-05-14.
- How severe is CVE-2026-42159?
- Medium severity. CVSS v3 base score is 5.4 out of 10.