Bug 2514255 (CVE-2026-73215)

Summary:	CVE-2026-73215 coturn: Coturn: Denial of Service due to incorrect port allocation
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in Coturn. An authenticated client can exploit a vulnerability by sending a specially crafted 'EVEN-PORT Allocate request' with a reservation bit set to zero. This causes the server to incorrectly mark an unused port as taken, leading to the permanent exhaustion of the relay port pool. Consequently, new connection allocations will fail, resulting in a Denial of Service (DoS) for legitimate users.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2514628, 2514629
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Description OSIDB Bzimport 2026-08-11 18:02:08 UTC

Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.17.0, turnports_allocate_even() in src/apps/relay/turn_ports.c marks the unused odd sibling port as TPS_TAKEN_ODD for an EVEN-PORT Allocate request with reservation bit R=0 even though no RTCP socket will release it, allowing an authenticated client to permanently exhaust the relay port pool and cause subsequent allocations to fail with STUN error 508. This issue is fixed in version 4.17.0.