CVE-2026-103602
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.
Published:Oct 2, 2026
Last Modified:Oct 28, 2026
EPS:Oct 2, 2026
EPSS Score:0.00289
CVSS Score:5.3
Affected Products
Vendor
Product
Action
Vendor
Bouncycastle
Product
Bc-csharp
Bouncycastle
Bc-csharp
Vendor
Legion Of The Bouncy Castle Inc.
Product
Bc-csharp
Legion Of The Bouncy Castle Inc.
Bc-csharp
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Related CVEs
References
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
