CVE-2026-8763
Received Received - Intake

Name Constraints Bypass in Bouncy Castle Java

Publication date: 2026-08-03

Last updated on: 2026-08-03

Assigner: bcorg

Description
In Bouncy Castle for Java before 1.85, Name Constraints bypass via trailing dot in rfc822Name and URI. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 1.0.2.7 (1.0.X series), 2.0.2 (2.0.X series) and 2.1.3 (2.1.X series).

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Meta Information

Published
2026-08-03
Last Modified
2026-08-03
Generated
2026-08-03
AI Q&A
2026-08-03
EPSS Evaluated
N/A
NVD
CVE-2026-8763
EUVD
EUVD-2026-52020

Affected Vendors & Products

Showing 5 associated CPEs
Vendor Product Version / Range
bouncy_castle bouncy_castle_for_java to 1.85 (exc)
bouncy_castle bouncy_castle_for_java_lts to 2.73.12 (exc)
bouncy_castle bouncy_castle_for_java_fips to 1.0.2.7 (exc)
bouncy_castle bouncy_castle_for_java_fips to 2.0.2 (exc)
bouncy_castle bouncy_castle_for_java_fips to 2.1.3 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-295 The product does not validate, or incorrectly validates, a certificate.

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Executive Summary

This vulnerability in Bouncy Castle for Java allows bypassing Name Constraints due to a trailing dot in rfc822Name and URI fields. It affects multiple versions of Bouncy Castle for Java, including LTS and FIPS variants.

Detection Guidance

This vulnerability involves Name Constraints bypass in Bouncy Castle for Java. Detection requires checking the installed Bouncy Castle version. Use commands like 'mvn dependency:tree' for Maven projects or 'gradle dependencies' for Gradle projects to inspect dependencies. If using BC-FJA, verify versions against the affected ranges (before 1.0.2.7, 2.0.2, 2.1.3, 1.85, or 2.73.12).

For systems using Bouncy Castle, check the version via 'java -jar bcprov-jdk18on-<version>.jar' or similar. If the version is within the vulnerable range, update immediately.

Impact Analysis

An attacker could exploit this to bypass security restrictions, potentially allowing unauthorized access or actions that should be restricted by certificate constraints.

Compliance Impact

This vulnerability allows bypassing name constraints in certificates, which could enable unauthorized access or impersonation. For compliance standards like GDPR or HIPAA, this could lead to violations of data protection requirements if exploited to gain unauthorized access to sensitive data.

Mitigation Strategies

Update Bouncy Castle for Java to version 1.85 or later. For LTS versions, upgrade to 2.73.12 or later. For BC-FJA, upgrade to bc-fips 1.0.2.7 (1.0.X), 2.0.2 (2.0.X), or 2.1.3 (2.1.X) or later.

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