What is CVE-2026-59639?
CVE-2026-59639 is a vulnerability in Bouncy Castle for Java where CMS `verifySignatures` incorrectly returns `true` for SignedData with zero signers. This allows unsigned data to be treated as valid. Users should update to Bouncy Castle 1.85, or the corresponding patched LTS and FIPS versions.
Azərbaycanca: CVE-2026-59639 Bouncy Castle Java kitabxanasında CMS imza yoxlanışı zəifliyidir. Kitabxana sıfır imzaçısı olan SignedData üçün `verifySignatures` metodunda səhvən `true` qaytarır, bu da imzasız məlumatın etibarlı kimi qəbul edilməsinə səbəb olur. Bouncy Castle 1.85, müvafiq LTS, FIPS versiyalarına yeniləmə tövsiyə olunur.
Related CVEs
link basis: same weakness class CWE-287; shared vendor: Bouncy Castle
FAQ2
In which method was the CVE-2026-59639 vulnerability discovered in the Bouncy Castle library?
The vulnerability was discovered in the `verifySignatures` method. This method incorrectly returns `true` for CMS SignedData with zero signers.
Which version is recommended to update to in order to remediate CVE-2026-59639?
It is recommended to update to Bouncy Castle 1.85, or the corresponding patched LTS and FIPS versions.
See also6
This explainer is AI-written from source data — skopnix's own reporting on this CVE; CVSS scores, vendors and versions are never invented. See NVD for the official record.