---
cve: "CVE-2026-59639"
severity: "HIGH"
cvss: 8.7
epss: "17%"
vendor: "Legion of the Bouncy Castle Inc."
kev: false
exploited: false
published: "2026-08-03 01:16:43"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-09T01:22:15+02:00"
---

# CVE-2026-59639

> 8.7 HIGH · 🧪 PoC

## Beschreibung

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).

## CVSS-Vektor

```
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
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 57fbd3c501f7a369f64eda311d6a709fc0bcae84 (Commit)
- 99ddc6dcc6782e6a76b0dd587c77e62eb7096ad0 (Commit)

## Referenzen

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

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-59639) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_