CVE-2026-59639 - Vulnerability Details - OpenCVE

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).

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

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References

Link	Providers
https://github.com/bcgit/bc-java/commit/99ddc6dcc6782e6a76b0dd587c77e62eb7096ad0
https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059639

History

Mon, 03 Aug 2026 05:30:00 +0000

Type	Values Removed	Values Added
References	https://github.com/bcgit/bc-java/wiki/CVE-2026-59639	https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059639

Mon, 03 Aug 2026 01:15:00 +0000

Type	Values Removed	Values Added
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).
Title		CMS verifySignatures returns true for SignedData with zero signers
Weaknesses		CWE-347
References		https://github.com/bcgit/bc-java/commit/99ddc6dcc6782e6a76b0dd587c77e62eb7096ad0 https://github.com/bcgit/bc-java/wiki/CVE-2026-59639
Metrics		cvssV4_0 `{'score': 8.7, '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'}`

MITRE

Status: PUBLISHED

Assigner: bcorg

Published: 2026-08-03T00:56:24.394Z

Updated: 2026-08-03T05:05:39.619Z

Reserved: 2026-07-06T06:58:29.263Z

Link: CVE-2026-59639

Vulnrichment

No data.

NVD

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Redhat

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OpenCVE Enrichment

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