CVE-2026-2645 MEDIUM

CVE-2026-2645: Acceptance of CertificateVerify Message before ClientKeyExchange in TLS 1.2

Vendor Wolfssl
Product wolfSSL
Weakness CWE-358
Published March 19, 2026
Last update March 19, 2026

CVSS base score

5.5/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P

What the vulnerability does

01Description

In wolfSSL 5.8.2 and earlier, a logic flaw existed in the TLS 1.2 server state machine implementation. The server could incorrectly accept the CertificateVerify message before the ClientKeyExchange message had been received. This issue affects wolfSSL before 5.8.4 (wolfSSL 5.8.2 and earlier is vulnerable, 5.8.4 is not vulnerable). In 5.8.4 wolfSSL would detect the issue later in the handshake. 5.9.0 was further hardened to catch the issue earlier in the handshake.

Key dates

02Disclosure timeline

March 19, 2026 CVE published
March 19, 2026 Record updated