2.3
LOW CVSS 4.0
CVE-2026-68554
Coturn: STUN attributes after MESSAGE-INTEGRITY are processed, letting on-path attackers modify authenticated TURN requests
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.

INFO

Published Date :

Aug. 19, 2026, 9:17 p.m.

Last Modified :

Aug. 20, 2026, 2:17 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-68554 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Coturn_project coturn
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 4.0 LOW [email protected]
Solution
Update Coturn to version 4.15.0 to fix authentication bypass via modified STUN requests.
  • Update Coturn to version 4.15.0.
  • Deploy TLS or DTLS for secure communication.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-68554 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-68554 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-68554 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 20, 2026

    Action Type Old Value New Value
    Added Reference https://github.com/coturn/coturn/security/advisories/GHSA-5538-7cxj-5jcc
    Added SSVC {'id': 'CVE-2026-68554', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-20T13:31:52.424319Z'}
  • New CVE Received by [email protected]

    Aug. 19, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'coturn', 'product': 'coturn', 'versions': [{'status': 'affected', 'version': '< 4.15.0'}]}]
    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.
    Added CVSS V4.0 AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-345
    Added CWE CWE-924
    Added Reference https://github.com/coturn/coturn/commit/ab762f334f511ea37ab4b703a47d5d683a5be978
    Added Reference https://github.com/coturn/coturn/releases/tag/4.15.0
    Added Reference https://github.com/coturn/coturn/security/advisories/GHSA-5538-7cxj-5jcc
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.