Threats Tagged 'cve-2026-63576'

An improper certificate validation vulnerability exists in the PkixNameConstraintValidator component of Legion of the Bouncy Castle Inc. bc-csharp before version 2.7.0. This flaw allows a name-constrained subordinate CA or an attacker with certificates containing chosen subjectAltName URIs to bypass URI name constraints during certification path validation. The issue arises because the host is extracted by string slicing without properly isolating the RFC 3986 authority component, causing the host compared against constraints to differ from the URI's actual host.

Improper certificate validation in PkixNameConstraintValidator (ExtractHostFromURL) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a name-constrained subordinate CA, or anyone able to obtain certificates with chosen subjectAltName URIs from such a CA, to bypass permitted or excluded uniformResourceIdentifier name constraints during certification path validation via a URI whose path, query, fragment or userinfo contains characters such as '@' or ':', because the host was extracted by string slicing without first isolating the RFC 3986 authority component, so the host compared against the constraints could differ from the URI's actual host.