wolfSSL up to 5.9.1 wolfSSL_X509_verify_cert certificate validation

Summaryinfo

A vulnerability, which was classified as problematic, was found in wolfSSL up to 5.9.1. This vulnerability affects the function wolfSSL_X509_verify_cert. Such manipulation leads to certificate validation. This vulnerability is referenced as CVE-2026-11999. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in wolfSSL up to 5.9.1. Affected by this issue is the function wolfSSL_X509_verify_cert. The manipulation with an unknown input leads to a certificate validation vulnerability. Using CWE to declare the problem leads to CWE-295. The product does not validate, or incorrectly validates, a certificate. Impacted is integrity. CVE summarizes:

X.509 trust-chain bypass (path-depth exhaustion) in the OpenSSL compatibility certificate verifier (wolfSSL_X509_verify_cert()). This affects only builds with --enable-opensslextra whose application calls X509_verify_cert() with caller-supplied untrusted intermediates; for those users it is critical, otherwise the library is unaffected. Native wolfSSL TLS/DTLS usage is not impacted. X509_verify_cert() returned success based only on the last verified link rather than on reaching a trust anchor: when the supplied chain is deeper than the verifier's maximum path depth (default 100), path building runs out of depth while still walking untrusted intermediates and the chain is accepted even though it never reaches a configured trust anchor, allowing acceptance of an attacker-controlled certificate. The default TLS handshake (WOLFSSL_VERIFY_PEER) is not affected; only applications doing manual or deferred verification through this API are.

The weakness was published by Corban Villa, Sohee Kim and Austin Chu. The advisory is available at github.com. This vulnerability is handled as CVE-2026-11999 since 06/11/2026. The exploitation is known to be difficult. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 06/25/2026). This vulnerability is assigned to T1587.003 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

• wolfSSL

Version

• 5.9.0
• 5.9.1

License

• open-source

Website

• Product: https://github.com/wolfSSL/wolfssl/

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CPE 2.2info

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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