CVE-2026-59639 · Symaro Security Advisory

Description

In Bouncy Castle for Java before 1.85, CMS verifySignatures returns true for SignedData with zero signers. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.12 (1.0.X series), 2.0.12 (2.0.X series) and 2.1.12 (2.1.X series).

Severity (CVSS)

Base score	8.7
Severity	High
Version	CVSS 4.0
Vector	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber
Provided by	CNA

Weaknesses

CWE-347 — CWE-347 Improper Verification of Cryptographic Signature

Affected products

Vendor	Product	Versions
Legion of the Bouncy Castle Inc.	BC-JAVA	0 to <1.85
Legion of the Bouncy Castle Inc.	BC-LTS-JAVA	2.73.0 to <2.73.12
Legion of the Bouncy Castle Inc.	BC-FJA	1.0.0 to <1.0.12; 2.0.0 to <2.0.12; 2.1.0 to <2.1.12

References

https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059639 (vendor-advisory)
https://github.com/bcgit/bc-java/commit/99ddc6dcc6782e6a76b0dd587c77e62eb7096ad0 (patch)

Authoritative sources

This page is a snapshot. For the latest enrichment and updates, view the record on CVE.org or the NVD.

Generated from the official CVE List on 03 Aug 2026 08:53 UTC.