Legion of the Bouncy Castle BC-JAVA up to 1.83 Private Key covert timing channel

Summaryinfo

A vulnerability categorized as problematic has been discovered in Legion of the Bouncy Castle BC-JAVA up to 1.83. The impacted element is an unknown function of the component Private Key Handler. Executing a manipulation can lead to covert timing channel. The identification of this vulnerability is CVE-2026-5598. The attack may be launched remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Legion of the Bouncy Castle BC-JAVA up to 1.83. It has been declared as problematic. This vulnerability affects an unknown functionality of the component Private Key Handler. The manipulation with an unknown input leads to a covert timing channel vulnerability. The CWE definition for the vulnerability is CWE-385. Covert timing channels convey information by modulating some aspect of system behavior over time, so that the program receiving the information can observe system behavior and infer protected information. As an impact it is known to affect confidentiality. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability was named CVE-2026-5598 since 04/05/2026. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 04/15/2026).

Upgrading to version 1.84 eliminates this vulnerability.

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Productinfo

Type

• Programming Language Software

Vendor

• Legion of the Bouncy Castle

Name

• BC-JAVA

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17
• 1.18
• 1.19
• 1.20
• 1.21
• 1.22
• 1.23
• 1.24
• 1.25
• 1.26
• 1.27
• 1.28
• 1.29
• 1.30
• 1.31
• 1.32
• 1.33
• 1.34
• 1.35
• 1.36
• 1.37
• 1.38
• 1.39
• 1.40
• 1.41
• 1.42
• 1.43
• 1.44
• 1.45
• 1.46
• 1.47
• 1.48
• 1.49
• 1.50
• 1.51
• 1.52
• 1.53
• 1.54
• 1.55
• 1.56
• 1.57
• 1.58
• 1.59
• 1.60
• 1.61
• 1.62
• 1.63
• 1.64
• 1.65
• 1.66
• 1.67
• 1.68
• 1.69
• 1.70
• 1.71
• 1.72
• 1.73
• 1.74
• 1.75
• 1.76
• 1.77
• 1.78
• 1.79
• 1.80
• 1.81
• 1.82
• 1.83

CPE 2.3info

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CPE 2.2info

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