CVE-2026-63578: legion of the bouncy castle inc. bc-csharp

Vulnerability summary

CVE-2026-63578 is a high (CVSS 7.1) vulnerability in legion of the bouncy castle inc. bc-csharp. EPSS estimates a 0.33% chance of exploitation in the next 30 days, higher than 24.8% of scored vulnerabilities.

Timeline

1. 02-10-2026
   PublishedVulnerability first disclosed.
2. 06-10-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.