Improper Verification of Cryptographic Signature in Bouncy Castle for Java and Bouncy Castle for Java LTS - CVE-2026-12860

Vulnerability identifier: #VU146442

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-2026-12860

CWE-ID: CWE-347

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to bypass RSA PKCS#1 signature verification.

The vulnerability exists due to improper signature verification in RSA PKCS#1 verification when processing the NULL-omitted path. A remote attacker can provide a crafted signature to bypass RSA PKCS#1 signature verification.

Bouncy Castle for Java
Bouncy Castle for Java LTS
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
Development Tools Module
IBM Sterling Control Center
IBM Maximo Application Suite - Manage Component
Total Storage Service Console (TSSC) / TS4500 IMC
Rational Developer for i
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
IBM Sterling Control Center - addressed in versions 6.3.1.0.11, 6.4.2.0.7
IBM Maximo Application Suite - Manage Component - addressed in versions 9.0.29, 9.1.21, 9.2.2
Rational Developer for i - update to 9.9.0.6
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
• SUSE update for bouncycastle
• Multiple vulnerabilities in IBM ApplinX
• Multiple vulnerabilities in IBM Maximo Application Suite - Manage Component
• Multiple vulnerabilities in IBM Rational Developer for i
• Multiple vulnerabilities in IBM Sterling Control Center
• Multiple vulnerabilities in Total Storage Service Console (TSSC) / TS4500 IMC