{"id":"CVE-2026-63575","state":"PUBLISHED","title":"PKCS#12 key derivation loops about 2^32 times on a zero or negative iteration count","description":"Loop with unreachable exit condition in the PKCS#12 key derivation (Pkcs12ParametersGenerator) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can supply a PKCS#12 (PFX) file, or a PKCS#8 encrypted private key that uses a PKCS#12 password-based encryption algorithm, to cause a denial of service through CPU exhaustion via an iteration count of zero or below, because the derivation loop ran until its counter equalled the count, so for such a count it wrapped through about 2^32 iterations before the MAC or the password could be checked. A 75-byte PFX file with a negative MacData iteration count kept Pkcs12Store.Load busy for many minutes.","publishedAt":"2026-10-02T07:06:31.876Z","updatedAt":"2026-10-02T19:25:38.391Z","severity":{"score":7.1,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","source":"bcorg"},"assigner":"bcorg","products":["Legion of the Bouncy Castle Inc. bc-csharp"],"affected":[{"vendor":"Legion of the Bouncy Castle Inc.","product":"bc-csharp","packageName":"BouncyCastle.Cryptography","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"2.7.0","versionType":"semver"}],"collectionURL":"https://www.nuget.org/packages/BouncyCastle.Cryptography","repo":"https://github.com/bcgit/bc-csharp","programFiles":["crypto/src/crypto/generators/Pkcs12ParametersGenerator.cs","crypto/src/security/PbeUtilities.cs","crypto/src/pkcs/Pkcs12Store.cs"]}],"references":["https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63575","https://github.com/bcgit/bc-csharp/commit/0c7a6dfd64c4a479577e35a728a766721b79aba7","https://github.com/bcgit/bc-csharp/commit/7c0ed15f9783c9595b1a53f3900136461fd944f4"],"weaknesses":["CWE-835"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/63xxx/CVE-2026-63575.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63575","state":"PUBLISHED","datePublished":"2026-10-02T07:06:31.876Z","dateUpdated":"2026-10-02T19:25:38.391Z","assignerShortName":"bcorg","assignerOrgId":"91579145-5d7b-4cc5-b925-a0262ff19630","dateReserved":"2026-07-16T23:50:45.118Z"},"containers":{"cna":{"title":"PKCS#12 key derivation loops about 2^32 times on a zero or negative iteration count","descriptions":[{"lang":"en","value":"Loop with unreachable exit condition in the PKCS#12 key derivation (Pkcs12ParametersGenerator) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can supply a PKCS#12 (PFX) file, or a PKCS#8 encrypted private key that uses a PKCS#12 password-based encryption algorithm, to cause a denial of service through CPU exhaustion via an iteration count of zero or below, because the derivation loop ran until its counter equalled the count, so for such a count it wrapped through about 2^32 iterations before the MAC or the password could be checked. 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