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Advisory details: gitlab / maven/org.bouncycastle/bcpkix-jdk14/CVE-2026-59639
Advisory ID gitlab/maven/org.bouncycastle/bcpkix-jdk14/CVE-2026-59639
Aliases CVE-2026-59639
Summary CMS verifySignatures returns true for SignedData with zero signers Affects Bouncy Castle for Java before 1.85. CMSSignedData.verifySignatures() iterates the signer set and returns true once the loop completes, without requiring that any signer be present. RFC 5652 allows a degenerate SignedData with an empty signerInfos set, and neither the ASN.1 layer nor SignerInformationStore rejects one. An attacker can submit a CMS or PKCS#7 blob carrying arbitrary content and no signers; applications treating the return value as proof of authenticity will accept unsigned content.
Status Published
Exploitability 0.5
Weighted Severity 0.0
Risk
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (3)
CWE-347 Improper Verification of Cryptographic Signature
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
cvssv3.1 https://gitlab.com/gitlab-org/advisories-community/-/blob/main/maven/org.bouncycastle/bcpkix-jdk14/CVE-2026-59639.yml
Reference id Reference type URL
99ddc6dcc6782e6a76b0dd587c77e62eb7096ad0 Other https://github.com/bcgit/bc-java/commit/99ddc6dcc6782e6a76b0dd587c77e62eb7096ad0
CVE-2026-59639 https://github.com/bcgit/bc-java/wiki/CVE-2026-59639
CVE-2026-59639 https://nvd.nist.gov/vuln/detail/CVE-2026-59639
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Found at https://gitlab.com/gitlab-org/advisories-community/-/blob/main/maven/org.bouncycastle/bcpkix-jdk14/CVE-2026-59639.yml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

There are no SSVC decisions available.