CVE-2026-59646
Received Received - Intake

Buffer Overflow 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, DTLS handshake reassembler allocates buffer from unchecked 24-bit length. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bctls-fips 1.0.24 (1.0.X series), 2.0.24 (2.0.X series) and 2.1.24 (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-2026-59646
EUVD
EUVD-2026-52028

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 bouncy_castle_fips to 1.0.24 (exc)
bouncy_castle bouncy_castle_fips to 2.0.24 (exc)
bouncy_castle bouncy_castle_fips to 2.1.24 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-789 The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.

Attack-Flow Graph

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Executive Summary

This vulnerability in Bouncy Castle for Java involves a buffer allocation issue in the DTLS handshake reassembler. It allows an attacker to exploit an unchecked 24-bit length, potentially leading to memory corruption or denial of service.

Detection Guidance

This vulnerability affects Bouncy Castle libraries in Java. Detection involves checking the installed version of Bouncy Castle libraries. Commands include: for Maven projects, check pom.xml for Bouncy Castle dependencies; for Java applications, inspect the classpath for bcprov, bctls, or bctls-fips JAR files. Compare versions against the patched releases (1.85, 2.73.12, 2.0.24, 2.1.24, or 1.0.24).

Impact Analysis

If you use affected versions of Bouncy Castle for Java, this vulnerability could allow remote attackers to cause crashes or execute arbitrary code, compromising system integrity and availability.

Compliance Impact

The vulnerability involves a buffer overflow in DTLS handshake reassembly due to unchecked 24-bit length allocation, which could lead to denial of service or potential data exposure. This may impact compliance with GDPR by risking unauthorized data access or processing disruptions, and with HIPAA by potentially exposing protected health information during transmission.

Mitigation Strategies

Upgrade 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 bctls-fips 1.0.24, 2.0.24, or 2.1.24 depending on your series.

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