CVE-2026-59639

In Bouncy Castle for Java before 1.85, CMS verifySignatures returns true for SignedData with zero signers. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.12 (1.0.X series), 2.0.12 (2.0.X series) and 2.1.12 (2.1.X series).

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/bcgit/bc-java/commit/99ddc6dcc6782e6a76b0dd587c77e62eb7096ad0	Patch
https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059639	Third Party Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:bouncycastle:bc-java::::::::
	cpe:2.3:a:bouncycastle:bcpkix-fips::::::::
	cpe:2.3:a:bouncycastle:bcpkix-fips::::::::
	cpe:2.3:a:bouncycastle:bcpkix-fips::::::::
	cpe:2.3:a:bouncycastle:bouncy_castle_for_java_lts::::::::

History

No history.

Information

Published : 2026-08-03 01:16

Updated : 2026-08-28 15:33

NVD link : CVE-2026-59639

Mitre link : CVE-2026-59639

CVE.ORG link : CVE-2026-59639

JSON object : View

Products Affected

bouncycastle

bouncy_castle_for_java_lts
bcpkix-fips
bc-java

CWE

CWE-347

Improper Verification of Cryptographic Signature

{"id": "CVE-2026-59639", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-59639", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-03T13:24:06.309527Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "91579145-5d7b-4cc5-b925-a0262ff19630", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 8.7, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/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", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "AMBER", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "91579145-5d7b-4cc5-b925-a0262ff19630", "affectedData": [{"repo": "https://github.com/bcgit/bc-java", "vendor": "Legion of the Bouncy Castle Inc.", "modules": ["pkix"], "product": "BC-JAVA", "versions": [{"status": "affected", "version": "0", "lessThan": "1.85", "versionType": "maven"}], "platforms": ["all"], "packageURL": "pkg:maven/org.bouncycastle/bcpkix-jdk18on", "packageName": "bcpkix", "programFiles": ["CMSSignedData"], "collectionURL": "https://www.bouncycastle.org/download/bouncy-castle-java/", "defaultStatus": "unaffected"}, {"repo": "https://github.com/bcgit/bc-lts-java", "vendor": "Legion of the Bouncy Castle Inc.", "modules": ["pkix"], "product": "BC-LTS-JAVA", "versions": [{"status": "affected", "version": "2.73.0", "lessThan": "2.73.12", "versionType": "maven"}], "platforms": ["all"], "packageURL": "pkg:maven/org.bouncycastle/bcpkix-lts8on", "packageName": "bcpkix-lts8on", "programFiles": ["CMSSignedData"], "collectionURL": "https://www.bouncycastle.org/download/bouncy-castle-java-lts/", "defaultStatus": "unaffected"}, {"vendor": "Legion of the Bouncy Castle Inc.", "product": "BC-FJA", "versions": [{"status": "affected", "version": "1.0.0", "lessThan": "1.0.12", "versionType": "maven"}, {"status": "affected", "version": "2.0.0", "lessThan": "2.0.12", "versionType": "maven"}, {"status": "affected", "version": "2.1.0", "lessThan": "2.1.12", "versionType": "maven"}], "platforms": ["all"], "packageURL": "pkg:maven/org.bouncycastle/bcpkix-fips", "packageName": "bcpkix-fips", "collectionURL": "https://www.bouncycastle.org/download/bouncy-castle-java-fips/", "defaultStatus": "unaffected"}]}], "published": "2026-08-03T01:16:43.700", "references": [{"url": "https://github.com/bcgit/bc-java/commit/99ddc6dcc6782e6a76b0dd587c77e62eb7096ad0", "tags": ["Patch"], "source": "91579145-5d7b-4cc5-b925-a0262ff19630"}, {"url": "https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059639", "tags": ["Third Party Advisory"], "source": "91579145-5d7b-4cc5-b925-a0262ff19630"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "91579145-5d7b-4cc5-b925-a0262ff19630", "description": [{"lang": "en", "value": "CWE-347"}]}], "descriptions": [{"lang": "en", "value": "In Bouncy Castle for Java before 1.85, CMS verifySignatures returns true for SignedData with zero signers. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.12 (1.0.X series), 2.0.12 (2.0.X series) and 2.1.12 (2.1.X series)."}], "lastModified": "2026-08-28T15:33:16.413", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:bouncycastle:bc-java:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "FA6A5663-2E62-44AA-8A64-A3CB0DC8813B", "versionEndExcluding": "1.85"}, {"criteria": "cpe:2.3:a:bouncycastle:bcpkix-fips:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C878934F-879A-4F9A-B81C-C284BF7797D4", "versionEndExcluding": "1.0.12"}, {"criteria": "cpe:2.3:a:bouncycastle:bcpkix-fips:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D0FF4FC3-75CF-4C5C-AEF1-342B8123264B", "versionEndExcluding": "2.0.12", "versionStartIncluding": "2.0.7"}, {"criteria": "cpe:2.3:a:bouncycastle:bcpkix-fips:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A5C3EAC6-7756-48AC-9129-A9BE7E11A8C7", "versionEndExcluding": "2.1.12", "versionStartIncluding": "2.1.8"}, {"criteria": "cpe:2.3:a:bouncycastle:bouncy_castle_for_java_lts:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F5ED4F42-08FF-4642-815D-1ED0C82FDBD2", "versionEndIncluding": "2.73.11"}], "operator": "OR"}]}], "sourceIdentifier": "91579145-5d7b-4cc5-b925-a0262ff19630"}