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Advisory details: gitlab / maven/org.bouncycastle/bcpkix-jdk15to18/CVE-2026-5588
Advisory ID gitlab/maven/org.bouncycastle/bcpkix-jdk15to18/CVE-2026-5588
Aliases CVE-2026-5588
GHSA-wg6q-6289-32hp
Summary Bouncy Castle Crypto Package For Java: Use of a Broken or Risky Cryptographic Algorithm vulnerability in bcpkix modules : 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.
Status Published
Exploitability 0.5
Weighted Severity 0.0
Risk
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (3)
CWE-327 Use of a Broken or Risky Cryptographic Algorithm
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
cvssv3.1 https://gitlab.com/gitlab-org/advisories-community/-/blob/main/maven/org.bouncycastle/bcpkix-jdk15to18/CVE-2026-5588.yml
Reference id Reference type URL
https://nvd.nist.gov/vuln/detail/CVE-2026-5588
656bae0dbd9b1521f840521ff786e78749fe3057 Other https://github.com/bcgit/bc-java/commit/656bae0dbd9b1521f840521ff786e78749fe3057
CVE%E2%80%902026%E2%80%905588 Advisory https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%905588
GHSA-wg6q-6289-32hp https://github.com/advisories/GHSA-wg6q-6289-32hp
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Found at https://gitlab.com/gitlab-org/advisories-community/-/blob/main/maven/org.bouncycastle/bcpkix-jdk15to18/CVE-2026-5588.yml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: SSVCv2/E:N/A:Y/T:P/P:M/B:A/M:M/D:T/2026-04-15T19:35:32Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/5xxx/CVE-2026-5588.json

Source Advisory: vulnrichment/CVE-2026-5588

View SSVC decision tree 
[{'Exploitation': 'none'},
 {'Automatable': 'yes'},
 {'Technical Impact': 'partial'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]