High severity · published Apr 15, 2026
CVE-2026-5588
PKIX draft CompositeVerifier accepts empty signature sequence as valid.
7.5
CVSS
0.8%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.8% · higher than 56% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
BC
BC-JAVA · Legion of the Bouncy Castle Inc.
1.67 before 1.80.2; 1.81 before 1.81.1; 1.82 before 1.84 · source: vendor
BC
BCPIX-LTS · Legion of the Bouncy Castle Inc.
2.73.7 before 2.73.11 · source: vendor
BC
BCPKIX-FIPS · Legion of the Bouncy Castle Inc.
2.0.6 before 2.0.11; 2.1.7 before 2.1.11 · source: vendor
OD
OpenShift Developer Tools and Services · Red Hat
All versions, or not specified · source: CISA
OD
OpenShift Developer Tools and Services 4.12 · Red Hat
All versions, or not specified · source: CISA
OD
OpenShift Developer Tools and Services 4.13 · Red Hat
All versions, or not specified · source: CISA
OD
OpenShift Developer Tools and Services 4.14 · Red Hat
All versions, or not specified · source: CISA
OD
OpenShift Developer Tools and Services 4.15 · Red Hat
All versions, or not specified · source: CISA
OD
OpenShift Developer Tools and Services 4.16 · Red Hat
All versions, or not specified · source: CISA
OD
OpenShift Developer Tools and Services 4.17 · Red Hat
All versions, or not specified · source: CISA
OD
OpenShift Developer Tools and Services 4.18 · Red Hat
All versions, or not specified · source: CISA
OD
OpenShift Developer Tools and Services 4.19 · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-5588
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-5588
github.com
https://github.com/bcgit/bc-java/commit/656bae0dbd9b1521f840521ff786e78749fe3057
github.com
https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%905588
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:11720
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:11721
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:13631
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:14272
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