CVE-2026-59650: Bouncycastle Bc-Java

Critical severity, CVSS 9.1. EPSS: 0.3% chance of exploitation in the next 30 days.

In Bouncy Castle for Java before 1.85, MTI/A0 DH agreement exponentiates unvalidated peer value. This issue also affects Bouncy Castle for Java LTS before 2.73.12.

Affected products

• Bouncycastle Bc-Java: before 1.85 (fixed in 1.85)
• Bouncycastle Bouncy Castle For Java LTS: up to and including 2.73.11

Published 2026-08-03. Last modified 2026-08-31.