OpenPGP CFB quick-check oracle active on symmetric/session-key paths

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-59640
StatePUBLISHED
Assignerbcorg
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-03 01:16:43 UTC
Updated2026-08-03 14:16:26 UTC
DescriptionIn 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).

Risk And Classification

Primary CVSS: v4.0 8.7 HIGH from 91579145-5d7b-4cc5-b925-a0262ff19630

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber

Problem Types: CWE-203 | CWE-203 CWE-203 Observable Discrepancy

VersionSourceTypeScoreSeverityVector
4.091579145-5d7b-4cc5-b925-a0262ff19630Secondary8.7HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS8.7HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/U:Amber

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
None
Availability
None
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Legion Of The Bouncy Castle Inc. BC-JAVA affected 1.85 maven all
CNA Legion Of The Bouncy Castle Inc. BC-LTS-JAVA affected 2.73.0 2.73.12 maven all
CNA Legion Of The Bouncy Castle Inc. BC-FJA affected 1.0.0 1.0.13 maven all
CNA Legion Of The Bouncy Castle Inc. BC-FJA affected 2.0.0 2.0.13 maven all
CNA Legion Of The Bouncy Castle Inc. BC-FJA affected 2.1.0 2.1.13 maven all

References

ReferenceSourceLinkTags
github.com/bcgit/bc-java/commit/6b94b1c146cec1f565d9a85847fae511af77503e 91579145-5d7b-4cc5-b925-a0262ff19630 github.com
github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059640 91579145-5d7b-4cc5-b925-a0262ff19630 github.com
github.com/bcgit/bc-java/wiki/CVE-2026-59640 MITRE github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Alex Gaynor in collaboration with Claude and Anthropic Research (en)

© CVE.report 2026

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