---
id: CVE-2026-68552
title: Coturn is a free open source implementation of TURN and STUN Server
summary: >-
  Coturn is a free open source implementation of TURN and STUN Server. Prior to
  4.15.0, an unauthenticated remote client can send a STUN message over TCP or
  TLS with a body-length field from 65520 through 65532, causing the uint16_t
  len va…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-190
published: '2026-08-19'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:20:38.860'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-68552'
references:
  - url: >-
      https://github.com/coturn/coturn/commit/ed32e1fb6c843f9cf9a28d91c541dfbf40874f25
    label: security-advisories@github.com
  - url: 'https://github.com/coturn/coturn/pull/1964'
    label: security-advisories@github.com
  - url: 'https://github.com/coturn/coturn/releases/tag/4.15.0'
    label: security-advisories@github.com
  - url: 'https://github.com/coturn/coturn/security/advisories/GHSA-m562-mf7x-q7rr'
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00315
epssPercentile: 0.24666
ingestedAt: '2026-09-09T21:22:45.544Z'
---

## Overview

Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.15.0, an unauthenticated remote client can send a STUN message over TCP or TLS with a body-length field from 65520 through 65532, causing the uint16_t len variable in stun_get_message_len_str() in src/client/ns_turn_msg.c to wrap when STUN_HEADER_LENGTH is added. The framing layer then consumes only 4 through 16 bytes, treats the remaining bytes as another message, desynchronizes the stream parser, and drops the attacking client's connection. Other clients and the server process are not affected. This issue is fixed in version 4.15.0.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.