CVE-2026-5588

PKIX draft CompositeVerifier accepts empty signature sequence as valid.

CVSS 6.3 MEDIUMEPSS 0.3%CWE-327

Vexday Risk Score

13Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 6.3EPSS 0.3%KEV nãoPoC —Patch referenciado

Lifecycle

15 Apr 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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: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

Affected products

Legion of the Bouncy Castle Inc. · BC-JAVA Legion of the Bouncy Castle Inc. · BCPIX-LTS Legion of the Bouncy Castle Inc. · BCPKIX-FIPS

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References

https://github.com/bcgit/bc-java/commit/656bae0dbd9b1521f840521ff786e78749fe3057 https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%905588