OpenPGP Weakness in Bouncy Castle for Java Affecting Multiple Versions
CVE-2026-59648

6.9MEDIUM

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-2026-59648?

A vulnerability in Bouncy Castle for Java prior to version 1.85 allows an attacker to exploit the OpenPGP Argon2 S2K feature, leading to potential memory manipulation. This flaw also impacts the LTS version before 2.73.12 and the FIPS versions before specified releases. Attackers can leverage this weakness by choosing memory configurations and passing parameters, which may lead to unauthorized access or other malicious activities.

Affected Version(s)

BC-FJA all 1.0.6 < 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%E2%80%902026%E2...
vendor-advisory
https://github.com/bcgit/bc-java/commit/c915cc3f7a8d58f5e...
patch

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
Low
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
.