---
id: CVE-2026-59640
title: >-
  In Bouncy Castle for Java before 1.85, OpenPGP CFB quick-check oracle active
  on symmetric/session-key paths
summary: >-
  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…
severity: high
cwe:
  - CWE-203
  - CWE-208
published: '2026-08-03'
updated: '2026-08-03'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-59640'
references:
  - url: >-
      https://github.com/bcgit/bc-java/commit/6b94b1c146cec1f565d9a85847fae511af77503e
    label: 91579145-5d7b-4cc5-b925-a0262ff19630
  - url: 'https://github.com/bcgit/bc-java/wiki/CVE-2026-59640'
    label: 91579145-5d7b-4cc5-b925-a0262ff19630
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-59640.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-59640'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2510200'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-59640'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-59640'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
ingestedAt: '2026-08-03T01:21:07.756Z'
epss: 0.00347
epssPercentile: 0.28085
vendor: Red Hat
product: Red Hat JBoss Enterprise Application Platform 7
affected:
  - jboss_enterprise_application_platform 7
  - single_sign_on 7
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cvssSource: vendor
---

## Overview

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).

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat JBoss Enterprise Application Platform 7, Red Hat Single Sign-On 7 · no fix planned: Red Hat JBoss Enterprise Application Platform 7, Red Hat Single Sign-On 7 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-59640.json)