Input validation error in OpenVPN Server - CVE-2026-35058
Published: April 24, 2026
Vulnerability identifier: #VU127529
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-35058
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: OpenVPN
Affected software:
OpenVPN Server
OpenVPN Server
Detailed vulnerability description
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to improper input validation in tls_crypt_v2_extract_client_key and tls_crypt_unwrap when processing a malformed control channel packet. A remote user can send a specially crafted packet to cause a denial of service.
Only setups using tls-crypt-v2 are vulnerable. Exploitation requires possession of a valid tls-crypt-v2 client key, or observation of a handshake using a key with a specific byte property, or injection into a live client session.
How to mitigate CVE-2026-35058
Install security update from vendor's website.