CVE-2026-11310 X.509 trust-chain bypass in wolfSSL_X509_verify_cert() via untrusted intermediate anchoring
Attackers can bypass certificate verification in wolfSSL when using OpenSSL compatibility mode with untrusted intermediates, accepting malicious certificates.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-11310?
CVE-2026-11310 is a high-severity vulnerability in Wolfssl Wolfssl, published on 25 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
X.509 trust-chain bypass in the OpenSSL compatibility certificate verifier (wolfSSL_X509_verify_cert()). This affects only builds with --enable-opensslextra (OPENSSL_EXTRA) and whose application validates certificates by calling X509_verify_cert() with caller-supplied untrusted intermediate certificates; for those users it is critical, otherwise the library is unaffected. In particular, native wolfSSL TLS/DTLS usage is not impacted. wolfSSL's X509_verify_cert() temporarily loads each caller-supplied untrusted intermediate into the certificate manager but failed to drop them before the trusted-store check, so an untrusted intermediate could anchor the path itself. An attacker can present a chain that never reaches a configured trust anchor and have it accepted, resulting in acceptance of an attacker-controlled certificate. This is certificate verification independent of TLS (e.g. S/MIME/CMS, code/firmware signing, JWT/JWS x5c), is not specific to any key type or algorithm, and a single untrusted intermediate suffices. The default wolfSSL TLS handshake (WOLFSSL_VERIFY_PEER) is not affected; only TLS applications doing manual or deferred peer verification through this API are, which also requires --enable-sessioncerts.
Weakness: CWE-295
Which versions are affected by CVE-2026-11310?
It affects 1 product.
Products include Wolfssl Wolfssl.
How do I fix CVE-2026-11310?
Apply the vendor's patch.
Is CVE-2026-11310 being exploited?
There is no known exploitation of CVE-2026-11310 in the wild and no public exploit code.
Other vulnerabilities in Wolfssl Wolfssl
Sources
Also known as DEBIAN-CVE-2026-11310, GHSA-h4wh-367g-85gm, JLSEC-2026-697, UBUNTU-CVE-2026-11310.