PT-2026-31865 · Openssl+2 · Openssl+2

Published 2026-04-10 · Updated 2026-04-11 · CVE-2026-5501

Positive Technologies (AI Summary)

CVSS v4.0

8.6

High

Base vector

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

Name of the Vulnerable Software and Affected Versions wolfSSL versions prior to 5.9.1

Description The wolfSSL X509 verify cert function within the OpenSSL compatibility layer does not properly check the signature of a certificate's leaf when an untrusted intermediate certificate with Basic Constraints CA:FALSE signed by a trusted root is provided. This allows an attacker with a valid certificate from a trusted Certificate Authority (CA), such as Let's Encrypt, to forge a certificate for any subject name and public key.

Recommendations Update to version 5.9.1 or later.

Fix

Improper Certificate Validation

Weakness Enumeration

CWE-295

Related Identifiers

CVE-2026-5501

Affected Products

Let'S Encrypt

Openssl

Wolfssl

References · 10

• https://osv.dev/vulnerability/UBUNTU-CVE-2026-5501 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-5501 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-5501 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-5501 · Security Note
• https://ubuntu.com/security/CVE-2026-5501 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-5501 · Security Note
• https://github.com/wolfSSL/wolfssl/pull/10102 · Note
• https://twitter.com/CVEnew/status/2042561778635411508 · Twitter Post
• https://twitter.com/CVEarity/status/2042920774093410741 · Twitter Post
• https://twitter.com/anonhaven_com/status/2042595274070053051 · Twitter Post