CVE-2026-62959: Coturn

High severity, CVSS 8.2. EPSS: 0.5% chance of exploitation in the next 30 days.

Coturn is a free open source implementation of TURN and STUN Server. From 4.5.2 through 4.14.0, when Coturn is started with --acme-redirect <URL> and exposes a plaintext-TCP listener, an unauthenticated remote client can send a single ordinary HTTP GET request and receive a 301 response whose Location header contains up to ~870 bytes of adjacent process heap memory. The leaked region is a recycled network receive buffer that is reused without being zeroed, so on a busy server it can contain data from other clients' requests (TURN credentials, OAuth tokens, relayed payloads). Root cause is a signed→unsigned conversion. This issue is fixed in version 4.15.0.

Affected products

• Coturn Coturn: from 4.5.2, before 4.15.0 (fixed in 4.15.0)

Published 2026-07-31. Last modified 2026-09-09.