Input validation error in Bouncy Castle for Java and Bouncy Castle for Java LTS - CVE-2026-59639

Vulnerability identifier: #VU146453

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-59639

CWE-ID: CWE-20

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to bypass CMS signature presence checks.

The vulnerability exists due to improper input validation in CMS verifySignatures when processing SignedData with zero signers. A remote attacker can supply crafted SignedData to bypass CMS signature presence checks.

Bouncy Castle for Java
Bouncy Castle for Java LTS
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
Development Tools Module
Crucible Server
Crucible Data Center
Crowd Data Center
IBM Maximo Application Suite - Manage Component
Confluence Data Center
Jira Service Management Data Center
Jira Software Data Center
Bamboo Data Center
ApplinX
bouncycastle-pkix
bouncycastle
bouncycastle-pg
bouncycastle-util

Install security update from vendor's website.

Bouncy Castle for Java - update to 1.85
Bouncy Castle for Java LTS - update to 2.73.12
Crucible Server - update to 4.9.14
Crucible Data Center - update to 4.9.14
Crowd Data Center - update to 7.2.3
IBM Maximo Application Suite - Manage Component - addressed in versions 9.0.29, 9.1.21, 9.2.2
Confluence Data Center - addressed in versions 9.2.24, 10.2.17
Jira Service Management Data Center - addressed in versions 10.3.25, 11.3.11
Jira Software Data Center - addressed in versions 10.3.25, 11.3.11
Bamboo Data Center - addressed in versions 10.2.22, 12.1.10
bouncycastle-pkix - update to 1.85-150200.3.38.1
bouncycastle - update to 1.85-150200.3.38.1
bouncycastle-pg - update to 1.85-150200.3.38.1
bouncycastle-util - update to 1.85-150200.3.38.1

• https://www.openwall.com/lists/oss-security/2026/08/04/2
• https://www.bouncycastle.org/resources/new-release-bouncy-castle-java-1-85/

• Multiple vulnerabilities in Bouncy Castle Java
• Multiple vulnerabilities in Bamboo Data Center
• SUSE update for bouncycastle
• Multiple vulnerabilities in IBM ApplinX
• Multiple vulnerabilities in IBM Maximo Application Suite - Manage Component
• Multiple vulnerabilities in Confluence Data Center
• Multiple vulnerabilities in Crucible Data Center and Crucible Server
• Multiple vulnerabilities in Crowd Data Center
• Multiple vulnerabilities in Jira Service Management Data Center
• Multiple vulnerabilities in Jira Software Data Center