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 (2.1.X series).

  • Published Aug 3, 2026
  • CVSS 9.3 critical
  • 0.3% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

In the news

CVE-2026-59638 at the National Vulnerability Database