# CVE-2026-59639: CMS verifySignatures returns true for SignedData with zero signers

> CVE-2026-59639: CMS verifySignatures returns true for SignedData with zero signers. CVSS 7.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-59639
Last updated: 2026-08-28T15:33:16Z

- Published: 2026-08-03 00:56 UTC · Updated: 2026-08-28 15:33 UTC · Assigner: bcorg
- CVSS: 7.5 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS: 0.24%, 15th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-347

## 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).

## Affected vendors and products

- Legion of the Bouncy Castle Inc.: BC-FJA
- Legion of the Bouncy Castle Inc.: BC-JAVA
- Legion of the Bouncy Castle Inc.: BC-LTS-JAVA

## Tracked companies

- [Confluence](https://rewindex.com/company/confluence.md)
- [Jira](https://rewindex.com/company/jira.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-59639)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-59639)
- [https://github.com/bcgit/bc-java/commit/99ddc6dcc6782e6a76b0dd587c77e62eb7096ad0](https://github.com/bcgit/bc-java/commit/99ddc6dcc6782e6a76b0dd587c77e62eb7096ad0)
- [https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059639](https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059639)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-59639 · Markdown: https://rewindex.com/cve/CVE-2026-59639.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-59639 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:48:28.611Z