CVE-2026-59639
published 2026-08-03CVE-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…
PriorityP342high7.5CVSS 3.1
AVNACLPRNUINSUCNIHAN
EPSS
0.16%
5.8th percentile
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).
Affected
14 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| bouncycastle | bc-java | < 1.85 | 1.85 |
| bouncycastle | bcpkix-fips | < 1.0.12 | 1.0.12 |
| bouncycastle | bcpkix-fips | >= 2.0.7 < 2.0.12 | 2.0.12 |
| bouncycastle | bcpkix-fips | >= 2.1.8 < 2.1.12 | 2.1.12 |
| bouncycastle | bouncy_castle_for_java_lts | <= 2.73.11 | — |
| debian | ceph | — | — |
| legion_of_the_bouncy_castle_inc | bc-fja | >= 1.0.0 < 1.0.12 | 1.0.12 |
| legion_of_the_bouncy_castle_inc | bc-fja | >= 2.0.0 < 2.0.12 | 2.0.12 |
| legion_of_the_bouncy_castle_inc | bc-fja | >= 2.1.0 < 2.1.12 | 2.1.12 |
| legion_of_the_bouncy_castle_inc | bc-java | < 1.85 | 1.85 |
| legion_of_the_bouncy_castle_inc | bc-lts-java | >= 2.73.0 < 2.73.12 | 2.73.12 |
| pki-core_10.6 | resteasy | — | — |
| pki-deps_10.6 | resteasy | — | — |
| redhat | resteasy | — | — |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
nvdv4.08.7HIGHCVSS: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
vendor_redhat8.7HIGH
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Red Hat
org.bouncycastle/bcpkix-jdk15on: org.bouncycastle/bcpkix-fips: Bouncy Castle for Java: Cryptographic signature bypass
vendor_redhat·2026-08-03·CVSS 8.7
CVE-2026-59639 [HIGH] CWE-347 org.bouncycastle/bcpkix-jdk15on: org.bouncycastle/bcpkix-fips: Bouncy Castle for Java: Cryptographic signature bypass
org.bouncycastle/bcpkix-jdk15on: org.bouncycastle/bcpkix-fips: Bouncy Castle for Java: Cryptographic signature bypass
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).
A flaw was found in Bouncy Castle for Java. The library's Cryptographic Message Syntax (CMS) component, which handles digital signature verification, incorrectly validates data that has no signers. This means that even if data is not digitally signed, the system might still consider it legitimate. This could allow an attacker to bypass critical security checks and potenti
VulDB
Legion of the Bouncy Castle Bouncy Castle for Java CMS verifySignatures improper authentication (WID-SEC-2026-2622)
vuldb·2026-08-04·CVSS 8.7
CVE-2026-59639 [HIGH] Legion of the Bouncy Castle Bouncy Castle for Java CMS verifySignatures improper authentication (WID-SEC-2026-2622)
A vulnerability was found in Legion of the Bouncy Castle Bouncy Castle for Java, Bouncy Castle for Java FIPS and Bouncy Castle for Java LTS. It has been rated as critical. Affected by this issue is the function verifySignatures of the component CMS. This manipulation causes improper authentication.
This vulnerability is handled as CVE-2026-59639. The attack can be initiated remotely. There is not any exploit available.
GHSA
In Bouncy Castle for Java before 1.85, CMS verifySignatures returns true for SignedData with zero signers.
ghsa_unreviewed·2026-08-03
CVE-2026-59639 [HIGH] CWE-347 In Bouncy Castle for Java before 1.85, CMS verifySignatures returns true for SignedData with zero signers.
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).
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-59639 ceph: Bouncy Castle for Java: Cryptographic signature bypass [fedora-all]
bugzilla·2026-08-25·CVSS 8.7
CVE-2026-59639 [HIGH] CVE-2026-59639 ceph: Bouncy Castle for Java: Cryptographic signature bypass [fedora-all]
CVE-2026-59639 ceph: Bouncy Castle for Java: Cryptographic signature bypass [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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).
Bugzilla
CVE-2026-59639 byte-buddy: Bouncy Castle for Java: Cryptographic signature bypass [fedora-all]
bugzilla·2026-08-25·CVSS 8.7
CVE-2026-59639 [HIGH] CVE-2026-59639 byte-buddy: Bouncy Castle for Java: Cryptographic signature bypass [fedora-all]
CVE-2026-59639 byte-buddy: Bouncy Castle for Java: Cryptographic signature bypass [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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).
Bugzilla
CVE-2026-59639 resteasy: Bouncy Castle for Java: Cryptographic signature bypass [fedora-all]
bugzilla·2026-08-25·CVSS 8.7
CVE-2026-59639 [HIGH] CVE-2026-59639 resteasy: Bouncy Castle for Java: Cryptographic signature bypass [fedora-all]
CVE-2026-59639 resteasy: Bouncy Castle for Java: Cryptographic signature bypass [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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).
Bugzilla
CVE-2026-59639 org.bouncycastle/bcpkix-jdk15on: org.bouncycastle/bcpkix-fips: Bouncy Castle for Java: Cryptographic signature bypass
bugzilla·2026-08-03·CVSS 8.7
CVE-2026-59639 [HIGH] CVE-2026-59639 org.bouncycastle/bcpkix-jdk15on: org.bouncycastle/bcpkix-fips: Bouncy Castle for Java: Cryptographic signature bypass
CVE-2026-59639 org.bouncycastle/bcpkix-jdk15on: org.bouncycastle/bcpkix-fips: Bouncy Castle for Java: Cryptographic signature bypass
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).
2026-08-03
Published