Bug 2499130 (CVE-2026-53450) - CVE-2026-53450 coturn: Coturn: Localhost services exposed via IPv4-mapped IPv6 address bypass
Summary: CVE-2026-53450 coturn: Coturn: Localhost services exposed via IPv4-mapped IPv...
Keywords:
Status: NEW
Alias: CVE-2026-53450
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-07-10 19:01 UTC by OSIDB Bzimport
Modified: 2026-07-10 20:08 UTC (History)
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Description OSIDB Bzimport 2026-07-10 19:01:55 UTC 
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.
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