Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.13.0, coturn rejects loopback peers by default unless allow-loopback-peers is enabled, but the default loopback guard can be bypassed by using the IPv4-mapped IPv6 peer address ::ffff:127.0.0.1 in a TURN XOR-PEER-ADDRESS attribute. ioa_addr_is_loopback checks for the literal IPv6 loopback shape before IPv4-mapped IPv6 handling, so good_peer_addr does not apply the default loopback rejection and an authenticated TURN client can expose services bound only to localhost on the coturn host through TURN relay traffic. This issue is fixed in version 4.13.0.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 10 Jul 2026 19:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Coturn
Coturn coturn |
|
| Vendors & Products |
Coturn
Coturn coturn |
Fri, 10 Jul 2026 19:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Fri, 10 Jul 2026 18:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.13.0, coturn rejects loopback peers by default unless allow-loopback-peers is enabled, but the default loopback guard can be bypassed by using the IPv4-mapped IPv6 peer address ::ffff:127.0.0.1 in a TURN XOR-PEER-ADDRESS attribute. ioa_addr_is_loopback checks for the literal IPv6 loopback shape before IPv4-mapped IPv6 handling, so good_peer_addr does not apply the default loopback rejection and an authenticated TURN client can expose services bound only to localhost on the coturn host through TURN relay traffic. This issue is fixed in version 4.13.0. | |
| Title | Coturn: IPv4-mapped 127.0.0.1 bypasses default loopback peer protection | |
| Weaknesses | CWE-918 | |
| References |
| |
| Metrics |
cvssV3_1
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-07-10T19:03:44.107Z
Reserved: 2026-06-09T16:31:21.494Z
Link: CVE-2026-53450
Updated: 2026-07-10T19:03:38.177Z
No data.
No data.
OpenCVE Enrichment
Updated: 2026-07-10T19:30:04Z
Weaknesses