{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-105794", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-10-05T20:37:19.364Z", "datePublished": "2026-10-06T14:14:54.483Z", "dateUpdated": "2026-10-06T14:14:54.483Z"}, "containers": {"cna": {"title": "MsQuic: Improper Certificate Validation in Microsoft.Native.Quic.MsQuic.OpenSSL", "problemTypes": [{"descriptions": [{"cweId": "CWE-295", "lang": "en", "description": "CWE-295: Improper Certificate Validation", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 9.1, "baseSeverity": "CRITICAL", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N", "version": "4.0"}}], "references": [{"name": "https://github.com/microsoft/msquic/security/advisories/GHSA-w5f4-fx9m-m4q7", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/microsoft/msquic/security/advisories/GHSA-w5f4-fx9m-m4q7"}, {"name": "https://github.com/microsoft/msquic/pull/6274", "tags": ["x_refsource_MISC"], "url": "https://github.com/microsoft/msquic/pull/6274"}, {"name": "https://github.com/microsoft/msquic/pull/6275", "tags": ["x_refsource_MISC"], "url": "https://github.com/microsoft/msquic/pull/6275"}, {"name": "https://github.com/microsoft/msquic/pull/6276", "tags": ["x_refsource_MISC"], "url": "https://github.com/microsoft/msquic/pull/6276"}, {"name": "https://github.com/microsoft/msquic/pull/6277", "tags": ["x_refsource_MISC"], "url": "https://github.com/microsoft/msquic/pull/6277"}, {"name": "https://github.com/microsoft/msquic/commit/0591586443cc73a2d2cfb679527d91a144b4a412", "tags": ["x_refsource_MISC"], "url": "https://github.com/microsoft/msquic/commit/0591586443cc73a2d2cfb679527d91a144b4a412"}, {"name": "https://github.com/microsoft/msquic/commit/508e811370df93e2ad848f5c78347d4fe4f65a91", "tags": ["x_refsource_MISC"], "url": "https://github.com/microsoft/msquic/commit/508e811370df93e2ad848f5c78347d4fe4f65a91"}, {"name": "https://github.com/microsoft/msquic/commit/90fd45498bf9b506b8556fb407088688474d6c81", "tags": ["x_refsource_MISC"], "url": "https://github.com/microsoft/msquic/commit/90fd45498bf9b506b8556fb407088688474d6c81"}, {"name": "https://github.com/microsoft/msquic/commit/a01333cf7c2659cce0ff03ef3f21e1ff15bb5b83", "tags": ["x_refsource_MISC"], "url": "https://github.com/microsoft/msquic/commit/a01333cf7c2659cce0ff03ef3f21e1ff15bb5b83"}, {"name": "https://github.com/microsoft/msquic/releases/tag/v2.4.20", "tags": ["x_refsource_MISC"], "url": "https://github.com/microsoft/msquic/releases/tag/v2.4.20"}, {"name": "https://github.com/microsoft/msquic/releases/tag/v2.5.11", "tags": ["x_refsource_MISC"], "url": "https://github.com/microsoft/msquic/releases/tag/v2.5.11"}, {"name": "https://github.com/microsoft/msquic/releases/tag/v2.6.1", "tags": ["x_refsource_MISC"], "url": "https://github.com/microsoft/msquic/releases/tag/v2.6.1"}], "affected": [{"vendor": "microsoft", "product": "msquic", "versions": [{"version": "< 2.4.20", "status": "affected"}, {"version": ">= 2.5.0, < 2.5.11", "status": "affected"}, {"version": ">= 2.6.0, < 2.6.1", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-06T14:14:54.483Z"}, "descriptions": [{"lang": "en", "value": "MsQuic is a cross-platform C implementation of the IETF QUIC protocol exposed to C, C++, C#, and Rust. Prior to 2.4.20, 2.5.11, and 2.6.1, MsQuic clients using the OpenSSL or QuicTLS TLS backend do not properly verify that a server certificate matches the intended target server hostname. An on-path attacker can therefore present a certificate that does not match the intended target hostname and spoof the server in a man-in-the-middle attack. The Schannel backend is not affected. This issue is fixed in versions 2.4.20, 2.5.11, and 2.6.1."}], "source": {"advisory": "GHSA-w5f4-fx9m-m4q7", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "msquic", "vendor": "microsoft", "versions": [{"status": "affected", "version": "< 2.4.20"}, {"status": "affected", "version": ">= 2.5.0, < 2.5.11"}, {"status": "affected", "version": ">= 2.6.0, < 2.6.1"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "MsQuic is a cross-platform C implementation of the IETF QUIC protocol exposed to C, C++, C#, and Rust. Prior to 2.4.20, 2.5.11, and 2.6.1, MsQuic clients using the OpenSSL or QuicTLS TLS backend do not properly verify that a server certificate matches the intended target server hostname. An on-path attacker can therefore present a certificate that does not match the intended target hostname and spoof the server in a man-in-the-middle attack. The Schannel backend is not affected. This issue is fixed in versions 2.4.20, 2.5.11, and 2.6.1."}], "id": "CVE-2026-105794", "lastModified": "2026-10-06T16:00:36.547", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 9.1, "baseSeverity": "CRITICAL", "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": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/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": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-10-06T15:17:16.260", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/microsoft/msquic/commit/0591586443cc73a2d2cfb679527d91a144b4a412"}, {"source": "security-advisories@github.com", "url": "https://github.com/microsoft/msquic/commit/508e811370df93e2ad848f5c78347d4fe4f65a91"}, {"source": "security-advisories@github.com", "url": "https://github.com/microsoft/msquic/commit/90fd45498bf9b506b8556fb407088688474d6c81"}, {"source": "security-advisories@github.com", "url": "https://github.com/microsoft/msquic/commit/a01333cf7c2659cce0ff03ef3f21e1ff15bb5b83"}, {"source": "security-advisories@github.com", "url": "https://github.com/microsoft/msquic/pull/6274"}, {"source": "security-advisories@github.com", "url": "https://github.com/microsoft/msquic/pull/6275"}, {"source": "security-advisories@github.com", "url": "https://github.com/microsoft/msquic/pull/6276"}, {"source": "security-advisories@github.com", "url": "https://github.com/microsoft/msquic/pull/6277"}, {"source": "security-advisories@github.com", "url": "https://github.com/microsoft/msquic/releases/tag/v2.4.20"}, {"source": "security-advisories@github.com", "url": "https://github.com/microsoft/msquic/releases/tag/v2.5.11"}, {"source": "security-advisories@github.com", "url": "https://github.com/microsoft/msquic/releases/tag/v2.6.1"}, {"source": "security-advisories@github.com", "url": "https://github.com/microsoft/msquic/security/advisories/GHSA-w5f4-fx9m-m4q7"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-295"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

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