Name constraints bypass via trailing dot in rfc822Name, dNSName and URI hosts
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.
CVE-2026-103602
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-103602
bc-csharp
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://github.com/bcgit/bc-csharp",
"vendor": "Legion of the Bouncy Castle Inc.",
"product": "bc-csharp",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "2.7.0",
"versionType": "semver"
}
],
"packageName": "BouncyCastle.Cryptography",
"programFiles": [
"crypto/src/pkix/PkixNameConstraintValidator.cs",
"crypto/src/pkix/NameConstraintUtilities.cs",
"crypto/src/pkix/NameConstraintEmail.cs",
"crypto/src/pkix/NameConstraintDns.cs",
"crypto/src/pkix/NameConstraintUri.cs"
],
"collectionURL": "https://www.nuget.org/packages/BouncyCastle.Cryptography",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-103602
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #8090 · Revision 1
- Added to Heist Feed
- Publisher date