SEPTEMBER 17, 2026
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Case File

CVE-2026-84303

MEDIUM · CVSS 6.3 EPSS 0.31% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-09-01 · Last synced 2026-09-17

CyberRota Analysis

AI-Generated

The xDS RBAC HTTP filter in gRPC-Go versions prior to 1.83.1 is vulnerable due to a failure to normalize header matcher names, which can lead to improper DENY policy enforcement and allow unauthorized requests to pass through. This vulnerability can also enable evasion of gRFC A41 validation, compromising request handling and security. Organizations using affected versions of gRPC-Go should prioritize upgrading to version 1.83.1 to mitigate these risks.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

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CVE
CVE-2026-84303
Severity
MEDIUM
CVSS
6.3
EPSS
0.31%

Original NVD 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.