CVE-2026-63568

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-63568
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.

7.5 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://github.com/bcgit/bc-csharp/commit/10a9862fad04bb0c832a78b10e71d9818d6d1a63 Patch
https://github.com/bcgit/bc-csharp/commit/65283bae66843d0d3c13c5e0272dbbe1c0d6aa04 Patch
https://github.com/bcgit/bc-csharp/commit/d16f08a53dd0a78eb3310bbe80c947c7e1677290 Patch
https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63568 Patch Vendor Advisory
Configurations

Configuration 1 (hide)

cpe:2.3:a:bouncycastle:bc-csharp:*:*:*:*:*:*:*:*
History

27 Oct 2026, 16:05

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 7.5
CPE cpe:2.3:a:bouncycastle:bc-csharp:*:*:*:*:*:*:*:*
First Time Bouncycastle bc-csharp
Bouncycastle
References () https://github.com/bcgit/bc-csharp/commit/10a9862fad04bb0c832a78b10e71d9818d6d1a63 - () https://github.com/bcgit/bc-csharp/commit/10a9862fad04bb0c832a78b10e71d9818d6d1a63 - Patch
References () https://github.com/bcgit/bc-csharp/commit/65283bae66843d0d3c13c5e0272dbbe1c0d6aa04 - () https://github.com/bcgit/bc-csharp/commit/65283bae66843d0d3c13c5e0272dbbe1c0d6aa04 - Patch
References () https://github.com/bcgit/bc-csharp/commit/d16f08a53dd0a78eb3310bbe80c947c7e1677290 - () https://github.com/bcgit/bc-csharp/commit/d16f08a53dd0a78eb3310bbe80c947c7e1677290 - Patch
References () https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63568 - () https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63568 - Patch, Vendor Advisory

02 Oct 2026, 07:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-10-02 07:16

Updated : 2026-10-27 16:05

NVD link : CVE-2026-63568

Mitre link : CVE-2026-63568

CVE.ORG link : CVE-2026-63568

JSON object : View

Products Affected

bouncycastle

  • bc-csharp
CWE
CWE-770

Allocation of Resources Without Limits or Throttling