CVE-2026-63578
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.
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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.
CVSS
- Versión: 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Puntuación base: 7.1
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.33%
- Percentil entre todas las CVEs puntuadas: 24
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1203Exploitation for Client Executionexecution85 % - Impacto principal
T1499.004Application or System Exploitationimpact90 %
UI:P (interacción del usuario para cargar clave privada encriptada) → T1203. CWE-770 (Allocation without limits) causa DoS por agotamiento de CPU mediante iteration count sin validar → T1499.004.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-770
Referencias
- https://github.com/bcgit/bc-csharp/commit/34a7c05f719c91c024f285c6b420d3c00f8019dd
- https://github.com/bcgit/bc-csharp/commit/54ea0b179ee627027829b44c45d6dd32e575bd67
- https://github.com/bcgit/bc-csharp/commit/7c0ed15f9783c9595b1a53f3900136461fd944f4
- https://github.com/bcgit/bc-csharp/commit/b57165ecb7790ecea08273b219d52d80c12990e4
- https://github.com/bcgit/bc-csharp/commit/c00fc018fca89c077c64dd2a2a2eb00ae7d97241
- https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63578
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-63578",
"cveTags": [],
"metrics": {
"cvssMetricV40": [
{
"type": "Secondary",
"source": "91579145-5d7b-4cc5-b925-a0262ff19630",
"cvssData": {
"Safety": "NOT_DEFINED",
"version": "4.0",
"Recovery": "NOT_DEFINED",
"baseScore": 7.1,
"Automatable": "NOT_DEFINED",
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"valueDensity": "NOT_DEFINED",
"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"exploitMaturity": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED",
"userInteraction": "PASSIVE",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "NONE",
"subIntegrityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"vulnAvailabilityImpact": "HIGH",
"availabilityRequirement": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"subConfidentialityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"confidentialityRequirement": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED"
}
}
]
},
"affected": [
{
"source": "91579145-5d7b-4cc5-b925-a0262ff19630",
"affectedData": [
{
"repo": "https://github.com/bcgit/bc-csharp",
"vendor": "Legion of the Bouncy Castle Inc.",
"product": "bc-csharp",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "2.7.0",
"versionType": "semver"
}
],
"packageName": "BouncyCastle.Cryptography",
"programFiles": [
"crypto/src/security/PbeUtilities.cs",
"crypto/src/cms/CMSPBEKey.cs"
],
"collectionURL": "https://www.nuget.org/packages/BouncyCastle.Cryptography",
"defaultStatus": "unaffected"
}
]
}
],
"published": "2026-10-02T08:17:03.087",
"references": [
{
"url": "https://github.com/bcgit/bc-csharp/commit/34a7c05f719c91c024f285c6b420d3c00f8019dd",
"source": "91579145-5d7b-4cc5-b925-a0262ff19630"
},
{
"url": "https://github.com/bcgit/bc-csharp/commit/54ea0b179ee627027829b44c45d6dd32e575bd67",
"source": "91579145-5d7b-4cc5-b925-a0262ff19630"
},
{
"url": "https://github.com/bcgit/bc-csharp/commit/7c0ed15f9783c9595b1a53f3900136461fd944f4",
"source": "91579145-5d7b-4cc5-b925-a0262ff19630"
},
{
"url": "https://github.com/bcgit/bc-csharp/commit/b57165ecb7790ecea08273b219d52d80c12990e4",
"source": "91579145-5d7b-4cc5-b925-a0262ff19630"
},
{
"url": "https://github.com/bcgit/bc-csharp/commit/c00fc018fca89c077c64dd2a2a2eb00ae7d97241",
"source": "91579145-5d7b-4cc5-b925-a0262ff19630"
},
{
"url": "https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63578",
"source": "91579145-5d7b-4cc5-b925-a0262ff19630"
}
],
"vulnStatus": "Undergoing Analysis",
"weaknesses": [
{
"type": "Secondary",
"source": "91579145-5d7b-4cc5-b925-a0262ff19630",
"description": [
{
"lang": "en",
"value": "CWE-770"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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."
}
],
"lastModified": "2026-10-02T14:44:52.247",
"sourceIdentifier": "91579145-5d7b-4cc5-b925-a0262ff19630"
}