Description
Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.15.0, an on-path attacker can append attributes after MESSAGE-INTEGRITY to an authenticated STUN request on plain UDP or TCP, adjust the STUN header length, and recompute the unkeyed FINGERPRINT while the original HMAC remains valid because it covers only the message prefix. Server-side parsing in src/server/ns_turn_server.c continues past MESSAGE-INTEGRITY through handle_turn_allocate(), handle_turn_create_permission(), handle_turn_refresh(), and handle_turn_command(), allowing trailing LIFETIME, XOR-PEER-ADDRESS, or ORIGIN attributes to override allocation lifetime, inject a permission, or bypass the origin check. TLS and DTLS deployments prevent this in-transit modification. This issue is fixed in version 4.15.0.
Published: 2026-08-19
Score: 2.3 Low
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

No analysis available yet.

Remediation

No remediation available yet.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Wed, 19 Aug 2026 21:00:00 +0000

Type Values Removed Values Added
Description Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.15.0, an on-path attacker can append attributes after MESSAGE-INTEGRITY to an authenticated STUN request on plain UDP or TCP, adjust the STUN header length, and recompute the unkeyed FINGERPRINT while the original HMAC remains valid because it covers only the message prefix. Server-side parsing in src/server/ns_turn_server.c continues past MESSAGE-INTEGRITY through handle_turn_allocate(), handle_turn_create_permission(), handle_turn_refresh(), and handle_turn_command(), allowing trailing LIFETIME, XOR-PEER-ADDRESS, or ORIGIN attributes to override allocation lifetime, inject a permission, or bypass the origin check. TLS and DTLS deployments prevent this in-transit modification. This issue is fixed in version 4.15.0.
Title Coturn: STUN attributes after MESSAGE-INTEGRITY are processed, letting on-path attackers modify authenticated TURN requests
Weaknesses CWE-345
CWE-924
References
Metrics cvssV4_0

{'score': 2.3, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N'}


Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-19T20:38:28.419Z

Reserved: 2026-07-30T19:56:44.102Z

Link: CVE-2026-68554

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-19T21:17:28.310

Modified: 2026-08-19T21:17:28.310

Link: CVE-2026-68554

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-345

    Insufficient Verification of Data Authenticity

  • CWE-924

    Improper Enforcement of Message Integrity During Transmission in a Communication Channel