PT-2026-33031 · Legion Of The Bouncy Castle+2 · Bc-Java+8

Published 2026-04-15 · Updated 2026-04-18 · CVE-2026-5588

OSV

CVSS v4.0

6.3

Medium

AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/U:Green

: Use of a Broken or Risky Cryptographic Algorithm vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA bcpkix on all (pkix modules).

PKIX draft CompositeVerifier accepts empty signature sequence as valid.

This issue affects BC-JAVA: from 1.49 before 1.84.

Exploit

Fix

Use of a Broken Cryptographic Algorithm

Weakness Enumeration

CWE-327

Related Identifiers

CVE-2026-5588

GHSA-WG6Q-6289-32HP

OPENSUSE-SU-2026:10571-1

Affected Products

Bc-Java

Bouncy Castle

Org.Bouncycastle:Bcpkix-Debug-Jdk14

Org.Bouncycastle:Bcpkix-Debug-Jdk15To18

Org.Bouncycastle:Bcpkix-Debug-Jdk18On

Org.Bouncycastle:Bcpkix-Jdk14

Org.Bouncycastle:Bcpkix-Jdk15On

Org.Bouncycastle:Bcpkix-Jdk15To18

Org.Bouncycastle:Bcpkix-Jdk18On

References · 11

• 🔥 https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%905588 · Exploit
• https://osv.dev/vulnerability/openSUSE-SU-2026:10571-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-5588 · Security Note
• https://osv.dev/vulnerability/GHSA-wg6q-6289-32hp · Vendor Advisory
• https://github.com/bcgit/bc-java/commit/656bae0dbd9b1521f840521ff786e78749fe3057 · Note
• https://github.com/bcgit/bc-java · Note
• https://suse.com/security/cve/CVE-2026-0636 · Note
• https://suse.com/security/cve/CVE-2025-14813 · Note
• https://suse.com/security/cve/CVE-2026-3505 · Note
• https://suse.com/security/cve/CVE-2026-5598 · Note
• https://suse.com/security/cve/CVE-2026-5588 · Note