# CVE-2026-5598

## Summary

- **CVE ID:** CVE-2026-5598
- **Severity:** HIGH
- **CVSS Score:** 8.9 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:U/S:P/AU:Y/U:Red)
- **CWE:** CWE-385
- **Published:** Apr 15, 2026
- **Last Modified:** Sep 10, 2026

## Description

Covert timing channel vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA core on all (core modules).
 Non-constant time comparisons risk private key leakage in FrodoKEM.

This issue affects BC-JAVA: from 2.17.3 before 1.84.

## Affected Products

- Legion of the Bouncy Castle Inc. — BC-JAVA (2.17.3)
- Legion of the Bouncy Castle Inc. — BC-JAVA (1.71)
- Legion of the Bouncy Castle Inc. — BC-JAVA (1.81)
- Legion of the Bouncy Castle Inc. — BC-JAVA (1.82)

## References

- [CNA](https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%905998)
- [CNA](https://github.com/bcgit/bc-java/commit/94abbd56413dfdac651fd878bc60253871ef5e87)
- [CNA](https://github.com/bcgit/bc-java/commit/8692e6b2b191fc4aafa32545c7a78bdb9bf110c5)
- [CNA](https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%905598)
- [redhat-SADP](https://access.redhat.com/security/cve/CVE-2026-5598)
- [redhat-SADP](https://bugzilla.redhat.com/show_bug.cgi?id=2458635)
- [redhat-SADP](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-5598.json)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:12267)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:18054)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:18055)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:12269)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:18059)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:53644)
- [redhat-SADP](https://access.redhat.com/errata/RHSA-2026:53806)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.90%
- **EPSS Percentile:** 57.5

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