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TI-2026-02258 Aliases CVE-2026-2645GHSA-cwc7-2fmx-fffq

Acceptance of CertificateVerify Message before ClientKeyExchange in TLS 1.2

Priority LOW 24CWE-358Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · High · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0013 2nd percentileScored 2026-11-07
Fix Fixed wolfSSL (wolfSSL): 5.8.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
wolfSSLwolfSSLbefore 5.8.45.8.4Patch availableCNA
  • wolfSSL VendorwolfSSL Affected before 5.8.4 Fixed in 5.8.4 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*before 5.8.4VulnerablewolfSSL
  • cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:* Versions before 5.8.4 Vulnerable ·wolfSSL

Remediation

  • Fix · CNA wolfSSL (wolfSSL) Fixed in 5.8.4

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-2645
  2. 2026-10-03 Alias added: GHSA-cwc7-2fmx-fffq

References

Patch 1

  • TI-2024-00830 SEGV and out of bounds memory read from malicious packet CVSS 3.1CRITICAL 9.1
  • TI-2022-18557 In wolfSSL before 5.5.1, malicious clients can cause a buffer overflow during a TLS 1.3… CVSS 3.1HIGH 7.5
  • TI-2025-10943 Potential DoS Vulnerability through Multiple KeyShareEntry with Same Group in TLS 1.3 ClientHello CVSS 4.0MEDIUM 6.3
  • TI-2017-09737 wolfSSL Bleichenbacher/ROBOT CVSS 3.0HIGH 7.5
  • TI-2019-08902 wolfSSL 4.0.0 has a Buffer Overflow in DoPreSharedKeys in tls13.c when a current identity… CVSS 3.1CRITICAL 9.8
  • TI-2017-02021 Improper certificate validation in wolfSSL CVSS 3.1CRITICAL 9.8
See all 150 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences