CVE-2026-68552

Coturn: uint16_t truncation overflow in STUN message length causes TCP stream framing bypass

Published: Aug 19, 2026Updated: Sep 9, 2026 Sources: CVE List NVDCWE-190

5.3MEDIUM

Description

Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.15.0, an unauthenticated remote client can send a STUN message over TCP or TLS with a body-length field from 65520 through 65532, causing the uint16_t len variable in stun_get_message_len_str() in src/client/ns_turn_msg.c to wrap when STUN_HEADER_LENGTH is added. The framing layer then consumes only 4 through 16 bytes, treats the remaining bytes as another message, desynchronizes the stream parser, and drops the attacking client's connection. Other clients and the server process are not affected. This issue is fixed in version 4.15.0.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:NUser Interaction

None

Scope

S:UScope

Unchanged

Impact

C:NConfidentiality

None

I:NIntegrity

None

A:LAvailability

Low

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Weaknesses

CWE-190

Affected Products

coturn

oss-project

coturnOn-prem

Networking Infrastructure / load-balancer-proxy

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

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Attack Graph

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1 technique

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References

https://github.com/coturn/coturn/security/advisories/GHSA-m562-mf7x-q7rr

github.com

https://github.com/coturn/coturn/pull/1964

github.com

https://github.com/coturn/coturn/commit/ed32e1fb6c843f9cf9a28d91c541dfbf40874f25

github.com

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