CVE-2026-103602CWE-295

CVE-2026-103602

published October 2, 2026

CVSS
8.2
EPSS
0%
Percentile
14.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS
8.2 · NONE
CVSS v4.0
8.2 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
EPSS
0.00243 · 14.7th percentile
Weakness
CWE-295 · Improper Certificate Validation
Published
2026-10-02T12:17Z
References (4)
EPSS history
Timeline
  • 03 OCT 03:41Z
    EPSS moved — → 0%
    epss
  • 02 OCT 07:10Z
    Name constraints bypass via trailing dot in rfc822Name, dNSName and URI hosts
    cvelistv5