XSS in Coturn
CVE-2026-43915
Coturn is a free open source implementation of TURN and STUN Server. Versions prior to 4.11.0 contain a stored cross-site scripting (XSS) vulnerability in the web-admin HTTPS interface. An attacker who can create a TURN allocation with a crafted USERNAME value can inject HTML/JavaScript that executes when an authenticated web-admin user views the TURN session list. In configurations using anonymous TURN access (--no-auth), this may be exploitable without TURN credentials. In authenticated deployments, exploitation requires valid TURN credentials or control over a provisioned username. This issue has been fixed in version 4.11.0.
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: 0.002 (13.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 13.6% 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: 0.002 · change: 0.000
Affected products
- Coturn — versions < 4.11.0
- Coturn Project
Weakness classification (CWE)
References
- github.com/coturn/coturn/security/advisories/GHSA-xxf5-9vj2-g84j (Vendor Advisory)
- github.com/coturn/coturn/releases/tag/4.11.0 (Release Notes)
Frequently asked questions
- What is CVE-2026-43915?
- CVE-2026-43915 is a medium-severity vulnerability in Coturn, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-06-18.
- How severe is CVE-2026-43915?
- Medium severity. CVSS v3 base score is 5.4 out of 10.