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OpenAdvisories
Medium · 5.8 CVE-2026-73212 EUVD-2026-56789

coturn peer-IP ACL canonicalization & scope bypass on the RFC 6062 TCP CONNECT relay path → internal-network SSRF and proven internal root RCE

Published Aug 11, 2026 · Updated Aug 11, 2026 · Assigned by GitHub_M

Description

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.

Affected products

VendorProductAffectedFixed
coturn coturn < 4.13.1 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 coturn 4.14.0-1 —
Debian 13 coturn No fix yet —
Debian 12 coturn No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.04 LTS coturn No fix yet —
Ubuntu 24.04 LTS coturn No fix yet —
Ubuntu 22.04 LTS coturn No fix yet —
Ubuntu 20.04 LTS coturn No fix yet —
Ubuntu 18.04 LTS coturn No fix yet —
Show 1 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 16.04 LTS coturn No fix yet —
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed coturn 4.17.2-1.1 openSUSE-SU-2026:11617-1

Advisories 1

References