OpenPGP Subpacket Length Vulnerability in Bouncy Castle for Java and Affected Versions
CVE-2026-59649

8.7HIGH

Key Information:

Vendor

Legion Of The Bouncy Castle Inc.

Status
Bc-java
Bc-lts-java
Bc-fja
Vendor
CVE Published:
3 August 2026

What is CVE-2026-59649?

A vulnerability exists in Bouncy Castle for Java prior to version 1.85, where the length of OpenPGP user-attribute subpackets is only limited by the maximum memory available to the Java Virtual Machine (JVM). This can lead to excessive memory consumption or denial-of-service conditions. The issue also impacts the Bouncy Castle for Java LTS versions prior to 2.73.12 and the FIPS-compliant versions before bcpg-fips 1.0.13, 2.0.13, and 2.1.13. It is crucial for users to update to the latest versions to ensure protection against potential exploitation.

Affected Version(s)

BC-FJA all 1.0.0 < 1.0.13

BC-FJA all 2.0.0 < 2.0.13

BC-FJA all 2.1.0 < 2.1.13

References

https://github.com/bcgit/bc-java/wiki/CVE-2026-59649
vendor-advisory
https://github.com/bcgit/bc-java/commit/a43c40dc12c3e1c6c...
patch

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Alex Gaynor in collaboration with Claude and Anthropic Research
.