{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63575","assignerOrgId":"91579145-5d7b-4cc5-b925-a0262ff19630","state":"PUBLISHED","assignerShortName":"bcorg","dateReserved":"2026-07-16T23:50:45.118Z","datePublished":"2026-10-02T07:06:31.876Z","dateUpdated":"2026-10-02T19:25:38.391Z"},"containers":{"cna":{"providerMetadata":{"orgId":"91579145-5d7b-4cc5-b925-a0262ff19630","shortName":"bcorg","dateUpdated":"2026-10-02T07:06:31.876Z"},"title":"PKCS#12 key derivation loops about 2^32 times on a zero or negative iteration count","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-835","description":"CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')","type":"CWE"}]}],"impacts":[{"descriptions":[{"lang":"en","value":"Denial of Service (CPU exhaustion: the PKCS#12 key derivation runs about 2^32 iterations)"}]}],"affected":[{"vendor":"Legion of the Bouncy Castle Inc.","product":"bc-csharp","collectionURL":"https://www.nuget.org/packages/BouncyCastle.Cryptography","packageName":"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"],"versions":[{"status":"affected","version":"0","lessThan":"2.7.0","versionType":"semver"}],"defaultStatus":"unaffected"}],"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. A 75-byte PFX file with a negative MacData iteration count kept Pkcs12Store.Load busy for many minutes.","supportingMedia":[{"type":"text/html","base64":false,"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. A 75-byte PFX file with a negative MacData iteration count kept Pkcs12Store.Load busy for many minutes."}]}],"references":[{"url":"https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63575","tags":["vendor-advisory"]},{"url":"https://github.com/bcgit/bc-csharp/commit/0c7a6dfd64c4a479577e35a728a766721b79aba7","tags":["patch"]},{"url":"https://github.com/bcgit/bc-csharp/commit/7c0ed15f9783c9595b1a53f3900136461fd944f4","tags":["patch"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":7.1,"vectorString":"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"}}],"credits":[{"lang":"en","value":"Paweł Łukasik (https://github.com/pawlos)","type":"finder"}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"Claude Opus 5.5"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-02T19:25:09.895774Z","id":"CVE-2026-63575","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-10-02T19:25:38.391Z"}}]}}