CVE-2026-59644: Bouncycastle Bc-Java

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

In Bouncy Castle for Java before 1.85, MLS hash-ratchet honours arbitrary 32-bit generation counter from sender.

Affected products

• Bouncycastle Bc-Java: before 1.85 (fixed in 1.85)

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