{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-27448", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-02-19T17:25:31.100Z", "datePublished": "2026-03-17T23:24:30.661Z", "dateUpdated": "2026-03-17T23:24:30.661Z"}, "containers": {"cna": {"title": "pyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callback", "problemTypes": [{"descriptions": [{"cweId": "CWE-636", "lang": "en", "description": "CWE-636: Not Failing Securely ('Failing Open')", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 1.7, "baseSeverity": "LOW", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U", "version": "4.0"}}], "references": [{"name": "https://github.com/pyca/pyopenssl/security/advisories/GHSA-vp96-hxj8-p424", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/pyca/pyopenssl/security/advisories/GHSA-vp96-hxj8-p424"}, {"name": "https://github.com/pyca/pyopenssl/commit/d41a814759a9fb49584ca8ab3f7295de49a85aa0", "tags": ["x_refsource_MISC"], "url": "https://github.com/pyca/pyopenssl/commit/d41a814759a9fb49584ca8ab3f7295de49a85aa0"}, {"name": "https://github.com/pyca/pyopenssl/blob/358cbf29c4e364c59930e53a270116249581eaa3/CHANGELOG.rst#L27", "tags": ["x_refsource_MISC"], "url": "https://github.com/pyca/pyopenssl/blob/358cbf29c4e364c59930e53a270116249581eaa3/CHANGELOG.rst#L27"}], "affected": [{"vendor": "pyca", "product": "pyopenssl", "versions": [{"version": ">= 0.14.0, < 26.0.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-03-17T23:24:30.661Z"}, "descriptions": [{"lang": "en", "value": "pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 0.14.0 and prior to version 26.0.0, if a user provided callback to `set_tlsext_servername_callback` raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for any security-sensitive behavior, this could allow bypassing it. Starting in version 26.0.0, unhandled exceptions now result in rejecting the connection."}], "source": {"advisory": "GHSA-vp96-hxj8-p424", "discovery": "UNKNOWN"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 0.14.0 and prior to version 26.0.0, if a user provided callback to `set_tlsext_servername_callback` raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for any security-sensitive behavior, this could allow bypassing it. Starting in version 26.0.0, unhandled exceptions now result in rejecting the connection."}], "id": "CVE-2026-27448", "lastModified": "2026-03-18T00:16:19.107", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 1.7, "baseSeverity": "LOW", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "UNREPORTED", "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:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/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": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-03-18T00:16:19.107", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/pyca/pyopenssl/blob/358cbf29c4e364c59930e53a270116249581eaa3/CHANGELOG.rst#L27"}, {"source": "security-advisories@github.com", "url": "https://github.com/pyca/pyopenssl/commit/d41a814759a9fb49584ca8ab3f7295de49a85aa0"}, {"source": "security-advisories@github.com", "url": "https://github.com/pyca/pyopenssl/security/advisories/GHSA-vp96-hxj8-p424"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-636"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

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