Vulnerability · Published Mar 19, 2026 · Assigned by wolfSSL
CVE-2026-2645Acceptance of CertificateVerify Message before ClientKeyExchange in TLS 1.2
Medium 5.5
In plain English
A medium-severity security flaw in wolfSSL from wolfSSL. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | wolfssl | 5.9.1-r0 | ALPINE-CVE-2026-2645 |
| Alpine:v3.24 | wolfssl | 5.9.0-r0 | ALPINE-CVE-2026-2645 |
| Debian:12 | wolfssl | no fix listed | DEBIAN-CVE-2026-2645 |
| Debian:13 | wolfssl | no fix listed | DEBIAN-CVE-2026-2645 |
| Ubuntu:22.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-2645 |
| Ubuntu:24.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-2645 |
| Ubuntu:25.10 | wolfssl | no fix listed | UBUNTU-CVE-2026-2645 |
| Ubuntu:26.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2026-2645 |
| Ubuntu:26.10 | wolfssl | no fix listed | UBUNTU-CVE-2026-2645 |
Affected products (as reported)
Weakness: CWE-358 · 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