CVE-2026-73216Public exploitNetwork attack vectorHinoki check available

Authenticated relay exhaustion via premature quota release

Published Aug 11, 2026 · Updated Aug 11, 2026

Resource exhaustion in coturn before 4.17.0 allows remote authenticated users to deny new relay allocations through mobility disconnects. In src/server/ns_turn_server.c, shutdown_client_connection() decrements user and total quota accounting before a first-stage close that retains the allocation, relay socket, session, and mobility ticket. The attack requires --mobility and a valid TURN account; repeated TCP allocations and immediate disconnects consume relay ports until later clients receive error 508.

CVSS severity6.5
Medium
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Resource exhaustion in coturn before 4.17.0 allows remote authenticated users to deny new relay allocations through mobility disconnects. In src/server/ns_turn_server.c, shutdown_client_connection() decrements user and total quota accounting before a first-stage close that retains the allocation, relay socket, session, and mobility ticket. The attack requires --mobility and a valid TURN account; repeated TCP allocations and immediate disconnects consume relay ports until later clients receive error 508.

The record

CVE
CVE-2026-73216
Published
Aug 11, 2026
Updated
Aug 11, 2026
Vendor
coturn
Product
coturn
Classifications
CWE-400, T1499.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.17.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

coturn · coturnversion=< 4.17.0

Published CVSS scores

6.5GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.003Application Exhaustion Flood

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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