Loopback Bypass in Coturn TURN and STUN Server Implementation
CVE-2026-53450

7.4HIGH

Key Information:

Vendor

Coturn

Status
Coturn
Vendor
CVE Published:
10 July 2026

What is CVE-2026-53450?

The Coturn TURN and STUN server implementation contains a vulnerability that allows authenticated clients to bypass the default rejection of loopback peers. This occurs due to improper handling of IPv4-mapped IPv6 addresses, particularly when using the address ::ffff:127.0.0.1. As a result, authenticated clients can potentially expose services that are meant to be restricted to localhost through TURN relay traffic. This issue has been addressed in version 4.13.0.

Affected Version(s)

coturn < 4.13.0

References

https://github.com/coturn/coturn/security/advisories/GHSA...
x_refsource_CONFIRM
https://github.com/coturn/coturn/commit/b057acbebe721c8f2...
x_refsource_MISC

CVSS V3.1

Score:
7.4
Severity:
HIGH
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.