---
id: CVE-2026-73212
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
  4.13.1, good_peer_addr() in src/server/ns_turn_server.c uses
  ioa_addr_in_range() in src/client/ns_turn_ioaddr.c without canonicalizing
  IPv4-compatible, 6to4, a…
severity: none
cwe:
  - CWE-284
  - CWE-918
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-2026-73212'
references:
  - url: >-
      https://github.com/coturn/coturn/commit/cf4b4952de48510d38415b96300da5fc674bfdda
    label: security-advisories@github.com
  - url: >-
      https://github.com/coturn/coturn/commit/d49ee56aa9fe748af064853d5e430eec1ccc3cbc
    label: security-advisories@github.com
  - url: 'https://github.com/coturn/coturn/pull/1945'
    label: security-advisories@github.com
  - url: 'https://github.com/coturn/coturn/pull/1947'
    label: security-advisories@github.com
  - url: 'https://github.com/coturn/coturn/releases/tag/4.13.1'
    label: security-advisories@github.com
  - url: 'https://github.com/coturn/coturn/security/advisories/GHSA-2x4g-wx24-48m4'
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00496
epssPercentile: 0.40007
ingestedAt: '2026-09-09T21:22:45.528Z'
---

## Overview

Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.13.1, good_peer_addr() in src/server/ns_turn_server.c uses ioa_addr_in_range() in src/client/ns_turn_ioaddr.c without canonicalizing IPv4-compatible, 6to4, and 64:ff9b::/96 NAT64 address forms, allowing an authenticated RFC 6062 TCP CONNECT relay client to bypass an IPv4 denied-peer-ip range when the Coturn host has a useful translation route. This issue is fixed in version 4.13.1.

## Remediation

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