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Vulnerability · Published Aug 19, 2026 · Assigned by GitHub_M

CVE-2026-68552Coturn: uint16_t truncation overflow in STUN message length causes TCP stream framing bypass

Medium 5.3

In plain English

A medium-severity integer overflow in coturn from coturn. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.5%top 55.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12coturnno fix listedDEBIAN-CVE-2026-68552
Debian:13coturnno fix listedDEBIAN-CVE-2026-68552
Debian:14coturn4.15.0-1DEBIAN-CVE-2026-68552
Ubuntu:22.04:LTScoturnno fix listedUBUNTU-CVE-2026-68552
Ubuntu:24.04:LTScoturnno fix listedUBUNTU-CVE-2026-68552
Ubuntu:26.04:LTScoturnno fix listedUBUNTU-CVE-2026-68552
Ubuntu:26.10coturnno fix listedUBUNTU-CVE-2026-68552

Affected products (as reported)

VendorProductVersions
coturn coturn < 4.15.0

Weakness: CWE-190 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References