Coturn: uint16_t truncation overflow in STUN message length causes TCP stream framing bypass
Published Aug 19, 2026
5.3
MEDIUMCVSS 3.1
EPSS 0.52%
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 products
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- Version < 4.15.0StatusaffectedConstraints-
- Version
No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
References (5)
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-63079 Advisory
- https://github.com/coturn/coturn/commit/ed32e1fb6c843f9cf9a28d91c541dfbf40874f25 x_refsource_MISC
- https://github.com/coturn/coturn/pull/1964 x_refsource_MISC
- https://github.com/coturn/coturn/releases/tag/4.15.0 x_refsource_MISC
- https://github.com/coturn/coturn/security/advisories/GHSA-m562-mf7x-q7rr x_refsource_CONFIRM
| Link | Providers | Tags |
|---|---|---|
| https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-63079 | Advisory | |
| https://github.com/coturn/coturn/commit/ed32e1fb6c843f9cf9a28d91c541dfbf40874f25 | x_refsource_MISC | |
| https://github.com/coturn/coturn/pull/1964 | x_refsource_MISC | |
| https://github.com/coturn/coturn/releases/tag/4.15.0 | x_refsource_MISC | |
| https://github.com/coturn/coturn/security/advisories/GHSA-m562-mf7x-q7rr | x_refsource_CONFIRM |
Change history (0)
No recorded changes yet.