CVE-2026-63567

{"id": "CVE-2026-63567", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-63567", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-02T18:09:42.725922Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 3.6, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "91579145-5d7b-4cc5-b925-a0262ff19630", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 8.2, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/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": "NONE", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "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/crypto/engines/IesEngine.cs"], "collectionURL": "https://www.nuget.org/packages/BouncyCastle.Cryptography", "defaultStatus": "unaffected"}]}], "published": "2026-10-02T07:16:37.127", "references": [{"url": "https://github.com/bcgit/bc-csharp/commit/eaa42e1e8125b3e2e25e365c4194c7cd5932360b", "tags": ["Patch"], "source": "91579145-5d7b-4cc5-b925-a0262ff19630"}, {"url": "https://github.com/bcgit/bc-csharp/commit/f881400b761134160ec2a05fd27c3e569453788d", "tags": ["Patch"], "source": "91579145-5d7b-4cc5-b925-a0262ff19630"}, {"url": "https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63567", "tags": ["Patch", "Vendor Advisory"], "source": "91579145-5d7b-4cc5-b925-a0262ff19630"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "91579145-5d7b-4cc5-b925-a0262ff19630", "description": [{"lang": "en", "value": "CWE-203"}]}], "descriptions": [{"lang": "en", "value": "Observable discrepancy in IesEngine.DecryptBlock in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote attacker who has captured an IES or ECIES ciphertext, and who can submit modified ciphertexts for decryption under the same key pair, to recover its plaintext via a CBC padding-oracle attack, because in block-cipher mode the engine decrypts the ciphertext and removes its padding before verifying the MAC. A padding failure is therefore reported with a different error message, and without the MAC computation, compared with a MAC failure. Only applications that construct IesEngine directly with a padded block cipher, such as AES in CBC mode with PKCS#7 padding, are affected; stream-mode IES is not."}], "lastModified": "2026-10-27T16:20:42.560", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:bouncycastle:bc-csharp:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "21A715E8-41BE-47EB-833D-07B9908CCF31", "versionEndExcluding": "2.7.0"}], "operator": "OR"}]}], "sourceIdentifier": "91579145-5d7b-4cc5-b925-a0262ff19630"}