Allocation of resources without limits or throttling in the CMP/CRMF password-based MAC verifier (PKMacBuilder) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote unauthenticated attacker to cause a denial of service through CPU exhaustion via a CMP message or CRMF certificate request whose PBMParameter declares a very large iteration count, because PKMacBuilder enforced its iteration-count ceiling only when the caller had supplied an explicit maximum through the PKMacBuilder(IPKMacPrimitivesProvider, int) constructor. With any other constructor, ProtectedPkiMessage.Verify and CertificateRequestMessage.IsValidSigningKeyPop performed as many hash iterations as the sender requested, up to about 2^31, before the MAC could be checked.
Metrics
Affected Vendors & Products
References
History
Tue, 27 Oct 2026 16:15:00 +0000
| Type | Values Removed | Values Added |
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| First Time appeared |
Bouncycastle
Bouncycastle bc-csharp |
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| CPEs | cpe:2.3:a:bouncycastle:bc-csharp:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Bouncycastle
Bouncycastle bc-csharp |
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| Metrics |
cvssV3_1
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Sun, 04 Oct 2026 22:15:00 +0000
| Type | Values Removed | Values Added |
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| First Time appeared |
Legion Of The Bouncy Castle Inc.
Legion Of The Bouncy Castle Inc. bc-csharp |
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| Vendors & Products |
Legion Of The Bouncy Castle Inc.
Legion Of The Bouncy Castle Inc. bc-csharp |
Sat, 03 Oct 2026 06:30:00 +0000
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| Metrics |
ssvc
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Fri, 02 Oct 2026 07:15:00 +0000
| Type | Values Removed | Values Added |
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| Description | Allocation of resources without limits or throttling in the CMP/CRMF password-based MAC verifier (PKMacBuilder) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote unauthenticated attacker to cause a denial of service through CPU exhaustion via a CMP message or CRMF certificate request whose PBMParameter declares a very large iteration count, because PKMacBuilder enforced its iteration-count ceiling only when the caller had supplied an explicit maximum through the PKMacBuilder(IPKMacPrimitivesProvider, int) constructor. With any other constructor, ProtectedPkiMessage.Verify and CertificateRequestMessage.IsValidSigningKeyPop performed as many hash iterations as the sender requested, up to about 2^31, before the MAC could be checked. | |
| Title | Unbounded CMP/CRMF password-based MAC iteration count allows CPU exhaustion | |
| Weaknesses | CWE-770 | |
| References |
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| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: bcorg
Published: 2026-10-02T06:59:30.557Z
Updated: 2026-10-02T18:11:27.486Z
Reserved: 2026-07-16T23:48:46.076Z
Link: CVE-2026-63568
Updated: 2026-10-02T18:11:22.037Z
Status : Analyzed
Published: 2026-10-02T07:16:37.267
Modified: 2026-10-27T16:05:42.207
Link: CVE-2026-63568
No data.