---
id: CVE-2026-73216
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
  4.17.0, shutdown_client_connection() in src/server/ns_turn_server.c
  prematurely calls dec_quota() and releases bandwidth accounting during the
  first-stage clos…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-400
published: '2026-08-11'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T20:55:04.493'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-73216'
references:
  - url: >-
      https://github.com/coturn/coturn/commit/3c5b2615fd405c4e7c5bf3fbeef895c94a90671b
    label: security-advisories@github.com
  - url: 'https://github.com/coturn/coturn/releases/tag/4.17.0'
    label: security-advisories@github.com
  - url: 'https://github.com/coturn/coturn/security/advisories/GHSA-f6hc-79w3-p8pq'
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.0057
epssPercentile: 0.44977
ingestedAt: '2026-09-09T21:22:45.529Z'
---

## Overview

Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.17.0, shutdown_client_connection() in src/server/ns_turn_server.c prematurely calls dec_quota() and releases bandwidth accounting during the first-stage close of a mobility-enabled allocation while preserving the allocation, relay socket, session, and mobility ticket, allowing an authenticated client to bypass --user-quota and --total-quota and exhaust relay ports. This issue is fixed in version 4.17.0.

## Remediation

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