CVE-2026-84303
Severity not reportedgRPC-Go is the Go language implementation of gRPC.
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.
Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/grpc/grpc-go/commit/db9482836c298f234c896cf82ab68cafc78237f8 security-advisories@github.com
- https://github.com/grpc/grpc-go/commit/ebba6f3f1b206e2b4dc4d1d5a96d18430302c2fe security-advisories@github.com
- https://github.com/grpc/grpc-go/pull/9332 security-advisories@github.com
- https://github.com/grpc/grpc-go/pull/9335 security-advisories@github.com
- https://github.com/grpc/grpc-go/releases/tag/v1.83.1 security-advisories@github.com
- https://github.com/grpc/grpc-go/security/advisories/GHSA-qc2q-p7wx-3px3 security-advisories@github.com