{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-84303", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-09-01T16:17:43.078Z", "datePublished": "2026-09-01T18:14:37.870Z", "dateUpdated": "2026-09-01T18:14:37.870Z"}, "containers": {"cna": {"title": "gRPC-Go: xDS RBAC HTTP Filter bypass via mixed-case Header Matching and gRFC A41 validation evasion", "problemTypes": [{"descriptions": [{"cweId": "CWE-178", "lang": "en", "description": "CWE-178: Improper Handling of Case Sensitivity", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-863", "lang": "en", "description": "CWE-863: Incorrect Authorization", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 6.3, "baseSeverity": "MEDIUM", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N", "version": "4.0"}}], "references": [{"name": "https://github.com/grpc/grpc-go/security/advisories/GHSA-qc2q-p7wx-3px3", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/grpc/grpc-go/security/advisories/GHSA-qc2q-p7wx-3px3"}, {"name": "https://github.com/grpc/grpc-go/pull/9332", "tags": ["x_refsource_MISC"], "url": "https://github.com/grpc/grpc-go/pull/9332"}, {"name": "https://github.com/grpc/grpc-go/pull/9335", "tags": ["x_refsource_MISC"], "url": "https://github.com/grpc/grpc-go/pull/9335"}, {"name": "https://github.com/grpc/grpc-go/commit/db9482836c298f234c896cf82ab68cafc78237f8", "tags": ["x_refsource_MISC"], "url": "https://github.com/grpc/grpc-go/commit/db9482836c298f234c896cf82ab68cafc78237f8"}, {"name": "https://github.com/grpc/grpc-go/commit/ebba6f3f1b206e2b4dc4d1d5a96d18430302c2fe", "tags": ["x_refsource_MISC"], "url": "https://github.com/grpc/grpc-go/commit/ebba6f3f1b206e2b4dc4d1d5a96d18430302c2fe"}, {"name": "https://github.com/grpc/grpc-go/releases/tag/v1.83.1", "tags": ["x_refsource_MISC"], "url": "https://github.com/grpc/grpc-go/releases/tag/v1.83.1"}], "affected": [{"vendor": "grpc", "product": "grpc-go", "versions": [{"version": "< 1.83.1", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-01T18:14:37.870Z"}, "descriptions": [{"lang": "en", "value": "gRPC-Go is the Go language implementation of gRPC. Prior to 1.83.1, the xDS RBAC HTTP filter in internal/xds/httpfilter/rbac/rbac.go does not lowercase header matcher names in normalizeHeaderMatcher even though incoming metadata keys are lowercase. A DENY policy using a mixed-case name such as X-Role or User-Agent therefore does not match and fails open, allowing requests that should be rejected. The same case mismatch permits :Scheme or Grpc-Status to evade gRFC A41 validation and prevents Host from being rewritten to :authority. This issue is fixed in version 1.83.1."}], "source": {"advisory": "GHSA-qc2q-p7wx-3px3", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "grpc-go", "vendor": "grpc", "versions": [{"status": "affected", "version": "< 1.83.1"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "gRPC-Go is the Go language implementation of gRPC. Prior to 1.83.1, the xDS RBAC HTTP filter in internal/xds/httpfilter/rbac/rbac.go does not lowercase header matcher names in normalizeHeaderMatcher even though incoming metadata keys are lowercase. A DENY policy using a mixed-case name such as X-Role or User-Agent therefore does not match and fails open, allowing requests that should be rejected. The same case mismatch permits :Scheme or Grpc-Status to evade gRFC A41 validation and prevents Host from being rewritten to :authority. This issue is fixed in version 1.83.1."}], "id": "CVE-2026-84303", "lastModified": "2026-09-01T19:17:30.600", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.3, "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": "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:L/VI:L/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": "LOW", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-09-01T19:17:30.600", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/grpc/grpc-go/commit/db9482836c298f234c896cf82ab68cafc78237f8"}, {"source": "security-advisories@github.com", "url": "https://github.com/grpc/grpc-go/commit/ebba6f3f1b206e2b4dc4d1d5a96d18430302c2fe"}, {"source": "security-advisories@github.com", "url": "https://github.com/grpc/grpc-go/pull/9332"}, {"source": "security-advisories@github.com", "url": "https://github.com/grpc/grpc-go/pull/9335"}, {"source": "security-advisories@github.com", "url": "https://github.com/grpc/grpc-go/releases/tag/v1.83.1"}, {"source": "security-advisories@github.com", "url": "https://github.com/grpc/grpc-go/security/advisories/GHSA-qc2q-p7wx-3px3"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-178"}, {"lang": "en", "value": "CWE-863"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}