Bouncy Castle Has Covert Timing Channel Vulnerability

CVE-2026-5598 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

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 only affects users of the FrodoKEM algorithm involved in the decryption of encapsulations.

This issue affects BC-JAVA: from 1.71 to 1.80.1, 1.81, 1.82 to 1.83.

Fixed versions: 1.80.2, 1.81.1, 1.84

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
—
Source code
Browse source ↗
Published (advisory)
2026-04-17 18:31:50 UTC
Updated
2026-06-19 15:20:41 UTC
GitHub reviewed
2026-04-25 23:25:24 UTC
NVD published
2026-04-15

EPSS Score

Score Percentile
0.51% 39.50%

CVSS Scores

Base score Version Severity Vector
8.9 4.0 —
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 Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:H)
High confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:H)
High integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:H)
High confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:H)
High integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:U)
Unreported: no public PoC, no reported exploitation, and no known simplification tools.
Safety (supplemental) (S:P)
Present: impact meets IEC 61508 marginal, critical, or catastrophic safety consequence levels.
Automatable (supplemental) (AU:Y)
Yes: all four kill-chain steps (reconnaissance, weaponization, delivery, exploitation) can be automated.
Provider urgency (supplemental) (U:RED)
Red: provider rates highest urgency.

Identifiers

Type Value
GHSA GHSA-p93r-85wp-75v3 ↗
CVE CVE-2026-5598 ↗

CWEs

CWE id Name
CWE-385 Covert Timing Channel

Credits

  • marcelstoer (analyst)
  • jmini (analyst)

Affected packages (3)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
maven org.bouncycastle:bcprov-jdk15to18 >= 1.71, < 1.80.2 1.80.2 —
maven org.bouncycastle:bcprov-jdk14 >= 1.81, < 1.81.1 1.81.1 —
maven org.bouncycastle:bcprov-jdk18on >= 1.82, < 1.84 1.84 —

References

cvelogic Threat Intelligence