Timing based private key exposure in Bouncy Castle (CVE-2020-15522) | HOL Guard CVE

Medium · CVSS 5.1CVE-2020-15522GHSA-6XX3-RG99-GC3P

Timing based private key exposure in Bouncy Castle

Answer in brief

CVE-2020-15522 records a Medium severity (CVSS 5.1) vulnerability in Timing based private key exposure in Bouncy Castle. The current sources do not mark it as known exploited. The current feed maps org.bouncycastle:bc-fips (maven), org.bouncycastle:bcprov-ext-jdk15on (maven), org.bouncycastle:bcprov-ext-jdk16 (maven), org.bouncycastle:bcprov-jdk14 (maven) and additional mapped packages. Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 13, 2021Updated Sep 10, 2026Source checked Sep 10, 2026First seen by HOL Aug 7, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.1
Exploitation: Not marked as known exploited
Affected software: 9 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 5.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps org.bouncycastle:bc-fips (maven), org.bouncycastle:bcprov-ext-jdk15on (maven), org.bouncycastle:bcprov-ext-jdk16 (maven), org.bouncycastle:bcprov-jdk14 (maven) and additional mapped packages. Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
org.bouncycastle:bc-fipsmaven	>=0 <1.0.2.1	1.0.2.1
org.bouncycastle:bcprov-ext-jdk15onmaven	>=0 <1.66	1.66
org.bouncycastle:bcprov-ext-jdk16maven	>=0 <1.66	1.66
org.bouncycastle:bcprov-jdk14maven	>=0 <1.66	1.66
org.bouncycastle:bcprov-jdk15maven	>=0 <1.66	1.66
org.bouncycastle:bcprov-jdk15onmaven	>=0 <1.66	1.66
org.bouncycastle:bcprov-jdk15to18maven	>=0 <1.66	1.66
org.bouncycastle:bcprov-jdk16maven	>=0 <1.66	1.66
BouncyCastlenuget	>=0 <1.8.7	1.8.7

Recommended response

Check inventory. Check lockfiles and deployed manifests for org.bouncycastle:bc-fips, org.bouncycastle:bcprov-ext-jdk15on, org.bouncycastle:bcprov-ext-jdk16.
Review the reported fix. Update org.bouncycastle:bc-fips to 1.0.2.1; org.bouncycastle:bcprov-ext-jdk15on to 1.66; org.bouncycastle:bcprov-ext-jdk16 to 1.66; org.bouncycastle:bcprov-jdk14 to 1.66; org.bouncycastle:bcprov-jdk15 to 1.66; org.bouncycastle:bcprov-jdk15on to 1.66; org.bouncycastle:bcprov-jdk15to18 to 1.66; org.bouncycastle:bcprov-jdk16 to 1.66; BouncyCastle to 1.8.7 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 13, 2021
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Aug 7, 2026

Sources and claim methodology

Upstream source description

Bouncy Castle BC Java before 1.66, BC C# .NET before 1.8.7, BC-FJA before 1.0.2.1, BC before 1.66, 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.

Quoted source text, attributed separately from HOL analysis.