CVE-2026-63576
Description
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.
Is your site exposed to CVE-2026-63576?
Run a free security scan — no signup, results in seconds.
EPSS — Exploit Prediction
EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.
Weakness Type (CWE)
References
Frequently Asked Questions
What is CVE-2026-63576? +
How do I check if I'm vulnerable to CVE-2026-63576? +
Related Vulnerabilities
Elixir WebRTC is an Elixir implementation of the W3C WebRTC API. Prior to 0.15.1 and 0.16.1, missing DTLS peer certificate …
A certification validation weakness exists in communication between affected Omada devices and cloud controllers. Certificate identity verification does not adequately …
An improper certificate validation vulnerability in the Prisma® Access Agent for iOS enables an attacker to perform a man-in-the-middle (MitM) …
"This issue is limited to motherboards and does not affect laptops, desktop computers, or other endpoints." An insufficient validation vulnerability …
When the Amazon Redshift Python Connector is configured with the BrowserAzureOAuth2CredentialsProvider plugin, the driver skips the SSL certificate validation step …
An improper certificate validation vulnerability exists in AVTECH IP cameras, DVRs, and NVRs due to the use of wget with …