CVE-2026-12852: Bouncycastle Bc-Java

High severity, CVSS 7.5. EPSS: 0.3% chance of exploitation in the next 30 days.

In Bouncy Castle for Java before 1.85, MLS wire decoder allocates attacker-declared opaque length before bounds check.

Affected products

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

Published 2026-08-03. Last modified 2026-08-28.