{"id":"AZL-99696","summary":"CVE-2026-84303 affecting package grpc 1.62.3-1","details":"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.","modified":"2026-09-06T05:31:44Z","published":"2026-09-01T19:17:30Z","upstream":["CVE-2026-84303"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-84303"}],"affected":[{"package":{"name":"grpc","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/grpc"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"1.62.3-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-99696.json"}}],"schema_version":"1.9.0"}