CVE-2020-15522: Bouncycastle Bc-Csharp

Medium severity, CVSS 5.9. EPSS: 1.5% chance of exploitation in the next 30 days.

Bouncy Castle BC Java before 1.66, BC C# .NET before 1.8.7, BC-FJA before 1.0.1.2, 1.0.2.1, and BC-FNA before 1.0.1.1 have a timing issue within the EC math library that can expose information about the private key when an attacker is able to observe timing information for the generation of multiple deterministic ECDSA signatures.

Affected products

• Bouncycastle Bc-Csharp: before 1.8.7 (fixed in 1.8.7)
• Bouncycastle Bouncy Castle Fips .net API: before 1.0.1.1 (fixed in 1.0.1.1)
• Bouncycastle Fips Java API: before 1.0.1.2 (fixed in 1.0.1.2); from 1.0.2, before 1.0.2.1 (fixed in 1.0.2.1)
• Bouncycastle The Bouncy Castle Crypto Package For Java: before 1.66 (fixed in 1.66)

Published 2021-05-20. Last modified 2026-06-17.