PT-2026-31865 · Wolfssl · Wolfssl

Published 2026-04-10 · Updated 2026-04-10 · CVE-2026-5501

NVD

CVSS v4.0

8.6

High

AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

wolfSSL X509 verify cert in the OpenSSL compatibility layer accepts a certificate chain in which the leaf's signature is not checked, if the attacker supplies an untrusted intermediate with Basic Constraints CA:FALSE that is legitimately signed by a trusted root. An attacker who obtains any leaf certificate from a trusted CA (e.g. a free DV cert from Let's Encrypt) can forge a certificate for any subject name with any public key and arbitrary signature bytes, and the function returns WOLFSSL SUCCESS / X509 V OK. The native wolfSSL TLS handshake path (ProcessPeerCerts) is not susceptible and the issue is limited to applications using the OpenSSL compatibility API directly, which would include integrations of wolfSSL into nginx and haproxy.

Fix

Improper Certificate Validation

Weakness Enumeration

CWE-295

Related Identifiers

CVE-2026-5501

Affected Products

Wolfssl

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-5501 · Security Note
• https://twitter.com/CVEnew/status/2042561778635411508 · Twitter Post
• https://github.com/wolfSSL/wolfssl/pull/10102 · Note