CVE-2026-68552

MEDIUM 5.3

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

CVSS Score

5.3

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-190
Vendor	coturn
Product	coturn
Published	Aug 19, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Affected Versions

coturn / coturn

< 4.15.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: 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: https://github.com/coturn/coturn/releases/tag/4.15.0