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.
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Affected Vendors & Products
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References
History
Wed, 02 Sep 2026 04:00:00 +0000
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| First Time appeared |
Grpc
Grpc grpc-go |
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| Vendors & Products |
Grpc
Grpc grpc-go |
Tue, 01 Sep 2026 22:00:00 +0000
| Type | Values Removed | Values Added |
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| Description | 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. | |
| Title | gRPC-Go: xDS RBAC HTTP Filter bypass via mixed-case Header Matching and gRFC A41 validation evasion | |
| Weaknesses | CWE-178 CWE-863 |
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| References |
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| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-09-01T18:14:37.870Z
Reserved: 2026-09-01T16:17:43.078Z
Link: CVE-2026-84303
No data.
Status : Received
Published: 2026-09-01T19:17:30.600
Modified: 2026-09-01T19:17:30.600
Link: CVE-2026-84303
No data.
OpenCVE Enrichment
Updated: 2026-09-02T03:45:04Z