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OpenAdvisories
Medium · 5.5 CVE-2026-2645 EUVD-2026-13135

Acceptance of CertificateVerify Message before ClientKeyExchange in TLS 1.2

Published Mar 19, 2026 · Updated Mar 19, 2026 · Assigned by wolfSSL

Description

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.

Affected products

VendorProductAffectedFixed
wolfSSL wolfSSL < 5.8.4 5.8.4

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 13 wolfssl No fix yet —
Debian 12 wolfssl No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 wolfssl No fix yet —
Ubuntu 26.04 LTS wolfssl No fix yet —
Ubuntu 25.10 wolfssl No fix yet —
Ubuntu 24.04 LTS wolfssl No fix yet —
Ubuntu 22.04 LTS wolfssl No fix yet —
Show 3 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 20.04 LTS wolfssl No fix yet —
Ubuntu 18.04 LTS wolfssl No fix yet —
Ubuntu 16.04 LTS wolfssl No fix yet —
ReleasePackageFixed inAdvisory
Alpine v3.24 wolfssl 5.9.0-r0 —
Alpine v3.23 wolfssl 5.9.1-r0 —

References