{
    "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"
            }
        }
    }
}