Improper Handling of Case Sensitivity Affecting cerbos package, versions <0.55.0-r7


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.31% (24th percentile)

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  • Snyk IDSNYK-WOLFILATEST-CERBOS-19853118
  • published16 Sept 2026
  • disclosed1 Sept 2026

Introduced: 1 Sep 2026

NewCVE-2026-84303  (opens in a new tab)
CWE-178  (opens in a new tab)
CWE-863  (opens in a new tab)

How to fix?

Upgrade Wolfi cerbos to version 0.55.0-r7 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream cerbos package and not the cerbos package as distributed by Wolfi. See How to fix? for Wolfi relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1