8.6High

Bouncycastle Bc-Java

CVE-2026-12185

In Bouncy Castle for Java before 1.85, BKS/UBER keystore allocates from untrusted lengths before integrity check. This issue also affects Bouncy Castle for Java LTS before 2.73.12.

What this means for your business

  • It affects Bouncycastle Bc-Java. It matters if your company, or a supplier that handles your data, runs it.
  • An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
  • FIRST's prediction model gives it a 0.2% chance of attack attempts being seen in the next 30 days, ranking above 14% of all known flaws.

What to do

  1. 1Check whether your company or your suppliers run Bouncycastle Bc-Java, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
8.6 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
CVSS v4
7.1
Weakness
CWE-789
Assigned by
91579145-5d7b-4cc5-b925-a0262ff19630

Dates

Published
2026-08-03
Last modified
2026-08-28
Sources
NVD

Affected products

  • Bouncycastle Bc-Java- 1.85
  • Bouncycastle Bouncy Castle For Java Lts- 2.73.11

As listed in the NVD configuration data. Not a statement about your estate.

References