CVE-2026-12860
Received Received - Intake

RSA PKCS#1 Verification Flaw in Bouncy Castle for Java

Publication date: 2026-08-03

Last updated on: 2026-08-03

Assigner: bcorg

Description
In Bouncy Castle for Java before 1.85, RSA PKCS#1 verification skips last two hash bytes in NULL-omitted path. This issue also affects Bouncy Castle for Java LTS before 2.73.12.

CVSS Scores

EPSS Scores

Probability:
Percentile:

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-2026-12860
EUVD
EUVD-2026-52138

Affected Vendors & Products

Showing 2 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)

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-347 The product does not verify, or incorrectly verifies, the cryptographic signature for data.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

In Bouncy Castle for Java before version 1.85, the RSA PKCS#1 verification process has a flaw where it skips the last two hash bytes when following a NULL-omitted path. This issue also affects Bouncy Castle for Java LTS versions before 2.73.12.

Detection Guidance

Detection requires checking the Bouncy Castle Java library version. Use commands like 'mvn dependency:tree' for Maven projects or inspect the JAR file's manifest to verify if the version is before 1.85 (for Java) or 2.73.12 (for LTS).

Impact Analysis

This vulnerability could allow attackers to bypass signature verification, potentially leading to unauthorized access or data tampering. Systems using affected Bouncy Castle versions may accept invalid or malicious signatures as valid.

Compliance Impact

The vulnerability in Bouncy Castle for Java before 1.85 or LTS before 2.73.12 involves incorrect RSA PKCS#1 verification, potentially allowing signature bypasses. This could undermine cryptographic integrity in systems handling sensitive data, which may impact compliance with standards like GDPR (data integrity requirements) and HIPAA (secure data transmission).

Mitigation Strategies

Upgrade Bouncy Castle for Java to version 1.85 or later and Bouncy Castle for Java LTS to version 2.73.12 or later. Remove any older versions from your dependencies.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-12860. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart