PKIX draft CompositeVerifier accepts empty signature sequence as valid.
Summary
| CVE | CVE-2026-5588 |
|---|---|
| State | PUBLISHED |
| Assigner | bcorg |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-15 10:16:49 UTC |
| Updated | 2026-07-16 12:18:07 UTC |
| Description | Use of a Broken or Risky Cryptographic Algorithm vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA bcpkix on all (pkix modules), Legion of the Bouncy Castle Inc. BCPKIX-FIPS bcpkix on All (pkix modules), Legion of the Bouncy Castle Inc. BCPIX-LTS bcpkix on All (pkix modules). This vulnerability is associated with program files JcaContentVerifierProviderBuilder.Java, JcaContentVerfierProviderBuilder.Java. This issue affects BC-JAVA: from 1.67 before 1.80.2, from 1.81 before 1.81.1, from 1.82 before 1.84; BCPKIX-FIPS: from 2.0.6 before 2.0.11, from 2.1.7 before 2.1.11; BCPIX-LTS: from 2.73.7 before 2.73.11. |
Risk And Classification
Primary CVSS: v4.0 6.3 MEDIUM from 91579145-5d7b-4cc5-b925-a0262ff19630
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber
EPSS: 0.003920000 probability, percentile 0.315300000 (date 2026-07-20)
Problem Types: CWE-327 | CWE-347 | CWE-327 CWE-327 Use of a Broken or Risky Cryptographic Algorithm | CWE-347 Improper Verification of Cryptographic Signature
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 91579145-5d7b-4cc5-b925-a0262ff19630 | Secondary | 6.3 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 6.3 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/U:Amber |
| 3.1 | ADP | CVSS | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/errata/RHSA-2026:11721 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:14276 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:18054 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:17668 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%905588 | 91579145-5d7b-4cc5-b925-a0262ff19630 | github.com | |
| access.redhat.com/errata/RHSA-2026:18059 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | bugzilla.redhat.com | |
| access.redhat.com/errata/RHSA-2026:13631 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-5588.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:21772 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-5588 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:11720 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| github.com/bcgit/bc-java/commit/656bae0dbd9b1521f840521ff786e78749fe3057 | 91579145-5d7b-4cc5-b925-a0262ff19630 | github.com | |
| access.redhat.com/errata/RHSA-2026:14272 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:18055 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Nicholas Carlini using Claude, Anthropic (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-04-15T10:00:59.672Z | Reported to Red Hat. |
| ADP | 2026-04-15T09:06:15.617Z | Made public. |
Solutions
ADP: RHSA-2026:18054: Red Hat JBoss EAP 8.1 for RHEL 8
ADP: RHSA-2026:18055: Red Hat JBoss EAP 8.1 for RHEL 9
ADP: RHSA-2026:14276: Red Hat AMQ Broker 7.12.7
ADP: RHSA-2026:14272: Red Hat AMQ Broker 7.13.5
ADP: RHSA-2026:13631: Red Hat Build of Apache Camel 4.14 for Quarkus 3.27
ADP: RHSA-2026:18059: Red Hat JBoss Enterprise Application Platform 8.1
ADP: RHSA-2026:21772: Red Hat OpenShift Dev Spaces 3.28
ADP: RHSA-2026:17668: Red Hat build of Apache Camel 4.18.1 for Spring Boot 3.5.14
ADP: RHSA-2026:11720: Red Hat build of Quarkus 3.20.6.SP1
ADP: RHSA-2026:11721: Red Hat build of Quarkus 3.27.3.SP1
Workarounds
ADP: To mitigate this flaw, check that the signature sequence is not empty before passing any data to the CompositeVerifier for cryptographic validation. If the sequence is empty or null, explicitly reject the payload before it is processed.