Legion of the Bouncy Castle bc-csharp up to 2.6.x Password-Based Decryption PbeUtilities.GenerateCipherParameters allocation of resources

Summaryinfo

A vulnerability classified as problematic was found in Legion of the Bouncy Castle bc-csharp up to 2.6.x. This affects the function PbeUtilities.GenerateCipherParameters of the component Password-Based Decryption. Executing a manipulation can lead to allocation of resources. The identification of this vulnerability is CVE-2026-63578. The attack may be launched remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in Legion of the Bouncy Castle bc-csharp up to 2.6.x and classified as problematic. This vulnerability affects the function PbeUtilities.GenerateCipherParameters of the component Password-Based Decryption. The manipulation with an unknown input leads to a allocation of resources vulnerability. The CWE definition for the vulnerability is CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. As an impact it is known to affect availability. CVE summarizes:

Allocation of resources without limits in password-based private-key decryption (PbeUtilities.GenerateCipherParameters) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can supply an encrypted private key, such as a PKCS#8 EncryptedPrivateKeyInfo or "ENCRYPTED PRIVATE KEY" PEM file, to cause a denial of service through CPU exhaustion via an iteration count close to 2^31, because the count is taken from the unauthenticated algorithm parameters without an upper bound and the key derivation runs before the password or the data can be checked. PKCS#5 PBES1 and PBES2 (PBKDF2), the PKCS#12 PBE algorithms and CMS password recipients (CmsPbeKey) are affected. Loading PKCS#12 files with Pkcs12Store is covered by CVE-2026-63572, and a zero or negative count with the PKCS#12 algorithms by CVE-2026-63575.

The advisory is available at github.com. This vulnerability was named CVE-2026-63578 since 07/17/2026. The exploitation appears to be easy. The attack can be initiated remotely. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 2.7.0 eliminates this vulnerability.

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Productinfo

Vendor

• Legion of the Bouncy Castle

Name

• bc-csharp

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6

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CPE 2.2info

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