CVE-2026-59638

A flaw was found in Bouncy Castle for Java. The Java Secure Socket Extension JSSE hostname verifier incorrectly enables the Common Name CN fallback by default, despite it being documented as an opt-in feature. This misconfiguration could allow a remote attacker to bypass proper hostname validatio...

CVE-2026-59638

In Bouncy Castle for Java before 1.85, JSSE hostname verifier CN-fallback enabled by default despite documented opt-in. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS BC-FJA before bctls-fips 1.0.24 1.0.X series, 2.0.24 2.0.X series and 2.1.24...

CVE-2026-59638: Improper Validation of Certificate with Host Mismatch

In Bouncy Castle for Java before 1.85, JSSE hostname verifier CN-fallback enabled by default despite documented opt-in. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS BC-FJA before bctls-fips 1.0.24 1.0.X series, 2.0.24 2.0.X series and 2.1.24...