7.5High

CVE-2026-5598

Covert timing channel vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA core on all (core modules). This vulnerability is associated with program files FrodoEngine.Java. This issue affects BC-JAVA: from 1.71 before 1.80.2, from 1.81 before 1.81.1, from 1.82 before 1.84.

What this means for your business

  • 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 0.9% chance of attack attempts being seen in the next 30 days, ranking above 57% of all known flaws.

What to do

  1. 1Ask your IT team or provider whether any of your systems use the affected product.
  2. 2If you do, follow the vendor's guidance. No patch reference has been published yet.

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
7.5 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v4
8.9
Weakness
CWE-385
Assigned by
91579145-5d7b-4cc5-b925-a0262ff19630

Dates

Published
2026-04-15
Last modified
2026-09-18
Sources
NVD

References