5.3Medium

CVE-2026-68552

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.

What this means for your business

  • An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
  • FIRST's prediction model gives it a 0.3% chance of attack attempts being seen in the next 30 days, ranking above 24% of all known flaws.

What to do

  1. 1Ask your IT team or provider whether any of your systems use the affected product.
  2. 2If you do, follow the vendor's guidance. No patch reference has been published yet.

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Scoring

CVSS
5.3 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness
CWE-190
Assigned by
security-advisories@github.com

Dates

Published
2026-08-19
Last modified
2026-09-09
Sources
NVD

References

CVE-2026-68552 | CyberBrief