{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-6550", "assignerOrgId": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "state": "PUBLISHED", "assignerShortName": "AMZN", "dateReserved": "2026-04-17T20:06:20.299Z", "datePublished": "2026-04-20T19:20:23.383Z", "dateUpdated": "2026-04-20T19:44:11.685Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "shortName": "AMZN", "dateUpdated": "2026-04-20T19:24:09.971Z"}, "title": "Key commitment policy bypass via shared key cache in AWS Encryption SDK for Python", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-757", "description": "CWE-757 Selection of Less-Secure algorithm during negotiation ('algorithm downgrade')", "type": "CWE"}]}], "impacts": [{"capecId": "CAPEC-620", "descriptions": [{"lang": "en", "value": "CAPEC-620 Drop Encryption Level"}]}], "affected": [{"vendor": "AWS", "product": "AWS Encryption SDK for Python", "versions": [{"status": "affected", "version": "2", "lessThanOrEqual": "2.5.1", "versionType": "custom"}, {"status": "affected", "version": "3", "lessThanOrEqual": "3.3.0", "versionType": "custom"}, {"status": "affected", "version": "4", "lessThanOrEqual": "4.0.4", "versionType": "custom"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "Cryptographic algorithm downgrade in the caching layer of Amazon AWS Encryption SDK for Python before version 3.3.1 and before version 4.0.5 might allow an authenticated local threat actor to bypass key commitment policy enforcement via a shared key cache, resulting in ciphertext that can be decrypted to multiple different plaintexts.\n\nTo remediate this issue, users should upgrade to version 3.3.1, 4.0.5 or above.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>Cryptographic algorithm downgrade in the caching layer of Amazon AWS Encryption SDK for Python before version 3.3.1 and before version 4.0.5 might allow an authenticated local threat actor to bypass key commitment policy enforcement via a shared key cache, resulting in ciphertext that can be decrypted to multiple different plaintexts.</p><p>To remediate this issue, users should upgrade to version 3.3.1, 4.0.5 or above.</p>"}]}], "references": [{"url": "https://aws.amazon.com/security/security-bulletins/2026-017-aws/", "tags": ["vendor-advisory"]}, {"url": "https://github.com/aws/aws-encryption-sdk-python/releases/tag/v4.0.5", "tags": ["patch"]}, {"url": "https://github.com/aws/aws-encryption-sdk-python/releases/tag/v3.3.1", "tags": ["patch"]}, {"url": "https://github.com/aws/aws-encryption-sdk-python/security/advisories/GHSA-v638-38fc-rhfv", "tags": ["third-party-advisory"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "LOCAL", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE", "baseSeverity": "MEDIUM", "baseScore": 4.7, "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N"}}, {"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "LOCAL", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "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": "MEDIUM", "baseScore": 5.7, "vectorString": "CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"}}], "credits": [{"lang": "en", "value": "1seal.org", "type": "finder"}], "source": {"discovery": "UNKNOWN"}, "x_generator": {"engine": "Vulnogram 1.0.1"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-04-20T19:44:04.637540Z", "id": "CVE-2026-6550", "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": "2026-04-20T19:44:11.685Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-6550", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-04-20T19:44:04.637540Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-04-20T19:44:07.480Z"}}], "cna": {"title": "Key commitment policy bypass via shared key cache in AWS Encryption SDK for Python", "source": {"discovery": "UNKNOWN"}, "credits": [{"lang": "en", "type": "finder", "value": "1seal.org"}], "impacts": [{"capecId": "CAPEC-620", "descriptions": [{"lang": "en", "value": "CAPEC-620 Drop Encryption Level"}]}], "metrics": [{"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.7, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}, {"format": "CVSS", "cvssV4_0": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 5.7, "Automatable": "NOT_DEFINED", "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "privilegesRequired": "LOW", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"vendor": "AWS", "product": "AWS Encryption SDK for Python", "versions": [{"status": "affected", "version": "2", "versionType": "custom", "lessThanOrEqual": "2.5.1"}, {"status": "affected", "version": "3", "versionType": "custom", "lessThanOrEqual": "3.3.0"}, {"status": "affected", "version": "4", "versionType": "custom", "lessThanOrEqual": "4.0.4"}], "defaultStatus": "unaffected"}], "references": [{"url": "https://aws.amazon.com/security/security-bulletins/2026-017-aws/", "tags": ["vendor-advisory"]}, {"url": "https://github.com/aws/aws-encryption-sdk-python/releases/tag/v4.0.5", "tags": ["patch"]}, {"url": "https://github.com/aws/aws-encryption-sdk-python/releases/tag/v3.3.1", "tags": ["patch"]}, {"url": "https://github.com/aws/aws-encryption-sdk-python/security/advisories/GHSA-v638-38fc-rhfv", "tags": ["third-party-advisory"]}], "x_generator": {"engine": "Vulnogram 1.0.1"}, "descriptions": [{"lang": "en", "value": "Cryptographic algorithm downgrade in the caching layer of Amazon AWS Encryption SDK for Python before version 3.3.1 and before version 4.0.5 might allow an authenticated local threat actor to bypass key commitment policy enforcement via a shared key cache, resulting in ciphertext that can be decrypted to multiple different plaintexts.\n\nTo remediate this issue, users should upgrade to version 3.3.1, 4.0.5 or above.", "supportingMedia": [{"type": "text/html", "value": "<p>Cryptographic algorithm downgrade in the caching layer of Amazon AWS Encryption SDK for Python before version 3.3.1 and before version 4.0.5 might allow an authenticated local threat actor to bypass key commitment policy enforcement via a shared key cache, resulting in ciphertext that can be decrypted to multiple different plaintexts.</p><p>To remediate this issue, users should upgrade to version 3.3.1, 4.0.5 or above.</p>", "base64": false}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-757", "description": "CWE-757 Selection of Less-Secure algorithm during negotiation ('algorithm downgrade')"}]}], "providerMetadata": {"orgId": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "shortName": "AMZN", "dateUpdated": "2026-04-20T19:24:09.971Z"}}}, "cveMetadata": {"cveId": "CVE-2026-6550", "state": "PUBLISHED", "dateUpdated": "2026-04-20T19:44:11.685Z", "dateReserved": "2026-04-17T20:06:20.299Z", "assignerOrgId": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "datePublished": "2026-04-20T19:20:23.383Z", "assignerShortName": "AMZN"}, "dataVersion": "5.2"}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "Cryptographic algorithm downgrade in the caching layer of Amazon AWS Encryption SDK for Python before version 3.3.1 and before version 4.0.5 might allow an authenticated local threat actor to bypass key commitment policy enforcement via a shared key cache, resulting in ciphertext that can be decrypted to multiple different plaintexts.\n\nTo remediate this issue, users should upgrade to version 3.3.1, 4.0.5 or above."}], "id": "CVE-2026-6550", "lastModified": "2026-04-20T20:16:49.283", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "NONE", "baseScore": 4.7, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 1.0, "impactScore": 3.6, "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "type": "Secondary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "attackVector": "LOCAL", "availabilityRequirement": "NOT_DEFINED", "baseScore": 5.7, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/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", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "type": "Secondary"}]}, "published": "2026-04-20T20:16:49.283", "references": [{"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "url": "https://aws.amazon.com/security/security-bulletins/2026-017-aws/"}, {"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "url": "https://github.com/aws/aws-encryption-sdk-python/releases/tag/v3.3.1"}, {"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "url": "https://github.com/aws/aws-encryption-sdk-python/releases/tag/v4.0.5"}, {"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "url": "https://github.com/aws/aws-encryption-sdk-python/security/advisories/GHSA-v638-38fc-rhfv"}], "sourceIdentifier": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-757"}], "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "type": "Secondary"}]}

{}