# CVE-2026-59640

## Summary

- **CVE ID:** CVE-2026-59640
- **Severity:** HIGH
- **CVSS Score:** 8.7 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/U:Amber)
- **CWE:** CWE-203
- **Published:** Aug 3, 2026
- **Last Modified:** Aug 3, 2026

## Description

In Bouncy Castle for Java before 1.85, OpenPGP CFB quick-check oracle active on symmetric/session-key paths. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpg-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).

## Affected Products

- Legion of the Bouncy Castle Inc. — BC-JAVA (0)
- Legion of the Bouncy Castle Inc. — BC-LTS-JAVA (2.73.0)
- Legion of the Bouncy Castle Inc. — BC-FJA (1.0.0)
- Legion of the Bouncy Castle Inc. — BC-FJA (2.0.0)
- Legion of the Bouncy Castle Inc. — BC-FJA (2.1.0)

## References

- [CNA](https://github.com/bcgit/bc-java/wiki/CVE-2026-59640)
- [CNA](https://github.com/bcgit/bc-java/commit/6b94b1c146cec1f565d9a85847fae511af77503e)
- [CNA](https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059640)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.22%
- **EPSS Percentile:** 12.1

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._