CVE-2026-103602

High

Description

Improper certificate validation in PkixNameConstraintValidator in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who controls, or can obtain certificates from, a name-constrained intermediate CA to have certificates accepted during PKIX certification path validation for email addresses, DNS names or URI hosts that lie within excluded subtrees applying to that CA, via an rfc822Name, dNSName or uniformResourceIdentifier name whose host ends with a dot, because names and constraints were compared without first removing the RFC 1034 root-label trailing dot, so a fully qualified host name did not match an excluded subtree for the same host written without the dot.

SeverityHigh
CVSS8.2
Exploit probability—
ProductLegion Of The Bouncy Castle Inc. Bc-csharp
PublishedOct 2, 2026
First seenOct 2, 2026
Weakness typeCWE-295CWE-295

How to fix

Affected products

ProductAffected versionsFixed in
Legion of the Bouncy Castle Inc. bc-csharpv < 2.7.02.7.0

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.