CVE-2026-59647
Undergoing Analysis Undergoing Analysis - In Progress

Password-MAC Bypass 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, CRMF/CMP password-MAC honours unbounded iteration count. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.12 (1.0.X series), 2.0.12 (2.0.X series) and 2.1.12 (2.1.X series).

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Meta Information

Published
2026-08-03
Last Modified
2026-08-03
Generated
2026-08-23
AI Q&A
2026-08-03
EPSS Evaluated
2026-08-22
NVD
CVE-2026-59647
EUVD
EUVD-2026-52027

Affected Vendors & Products

Showing 5 associated CPEs
Vendor Product Version / Range
bouncy_castle bouncy_castle to 1.85 (exc)
bouncy_castle bouncy_castle_lts to 2.73.12 (exc)
bouncy_castle bcpkix_fips to 1.0.12 (exc)
bouncy_castle bcpkix_fips to 2.0.12 (exc)
bouncy_castle bcpkix_fips to 2.1.12 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-770 The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

Attack-Flow Graph

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Executive Summary

In Bouncy Castle for Java before version 1.85, there is a vulnerability where the CRMF/CMP password-MAC does not properly limit the iteration count. This flaw allows the iteration count to be unbounded, potentially leading to excessive computational resources being used during password verification.

Detection Guidance

This vulnerability affects Bouncy Castle libraries in Java. To detect it, check the version of Bouncy Castle libraries in use. If using Maven, run: mvn dependency:tree | grep bouncycastle. For Gradle, use: gradle dependencies | grep bouncycastle. Compare versions against the patched releases (1.85, 2.73.12, or FIPS series 1.0.12/2.0.12/2.1.12).

Impact Analysis

This vulnerability could allow an attacker to perform denial-of-service attacks by forcing the system to use excessive resources during password verification. It may also lead to slower performance or system crashes if exploited repeatedly.

Compliance Impact

The vulnerability allows unbounded iteration count in CRMF/CMP password-MAC, which could lead to weak cryptographic protections. This may compromise data integrity and confidentiality, potentially violating requirements under GDPR for data security and HIPAA for protected health information.

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, update to bcpkix-fips 1.0.12, 2.0.12, or 2.1.12 depending on your series.

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