Stack-based buffer overflow in coTURN - CVE-2026-43994
Published: May 25, 2026
Vulnerability identifier: #VU132279
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-43994
CWE-ID: CWE-121
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: coTURN
Affected software:
coTURN
coTURN
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service and potentially execute arbitrary code.
The vulnerability exists due to stack-based buffer overflow in decode_oauth_token_gcm() when processing an attacker-supplied OAuth access token. A remote attacker can send a specially crafted STUN packet containing a crafted OAuth access token to cause a denial of service and potentially execute arbitrary code.
Only servers started with the --oauth mode are vulnerable, and exploitation occurs before AES-GCM authentication is verified.
How to mitigate CVE-2026-43994
Install security update from vendor's website.