---
id: CVE-2026-73215
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, turnports_allocate_even() in src/apps/relay/turn_ports.c marks the
  unused odd sibling port as TPS_TAKEN_ODD for an EVEN-PORT Allocate request
  with rese…
severity: none
cwe:
  - CWE-400
  - CWE-772
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-2026-73215'
references:
  - url: >-
      https://github.com/coturn/coturn/commit/4adbd82e78456e13109bf44deed4ec3aceb0bab2
    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-847g-qmc6-6m4r'
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00451
epssPercentile: 0.36541
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, turnports_allocate_even() in src/apps/relay/turn_ports.c marks the unused odd sibling port as TPS_TAKEN_ODD for an EVEN-PORT Allocate request with reservation bit R=0 even though no RTCP socket will release it, allowing an authenticated client to permanently exhaust the relay port pool and cause subsequent allocations to fail with STUN error 508. This issue is fixed in version 4.17.0.

## Remediation

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