Staging Environment: Content and features may be unstable or change without notice.
Advisory details: github_osv / GHSA-wg6q-6289-32hp
Advisory ID github_osv/GHSA-wg6q-6289-32hp
Aliases CVE-2026-5588
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 5.7
Risk 2.9
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (1)
CWE-327 Use of a Broken or Risky Cryptographic Algorithm
System Score Found at
cvssv4 6.3 https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-wg6q-6289-32hp/GHSA-wg6q-6289-32hp.json
generic_textual MODERATE
Reference id Reference type URL
https://github.com/bcgit/bc-java
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
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: 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:Green Found at https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-wg6q-6289-32hp/GHSA-wg6q-6289-32hp.json
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

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'}]

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'}]