CVE-2026-84303

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Source
https://cve.org/CVERecord?id=CVE-2026-84303
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84303.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-84303
Aliases
Downstream
AZL (1)
CGA (1172)
CLEANSTART (44)
DEBIAN (1)
ECHO (1)
MINI (1381)
openSUSE (31)
SUSE (29)
UBUNTU (1)
Related
openSUSE (31)
SUSE (29)
Published
2026-09-01T18:14:37Z
Modified
2026-10-28T02:30:40Z
Severity
  • 6.3 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
gRPC-Go: xDS RBAC HTTP Filter bypass via mixed-case Header Matching and gRFC A41 validation evasion
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.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-178",
        "CWE-863"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84303.json"
}
References

Affected packages

Git / github.com/grpc/grpc-go

Affected ranges

Type
GIT
Repo
https://github.com/grpc/grpc-go
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
1550d9e0cddb30ce99e61a2102e8294a49461e5e
Fixed
db9482836c298f234c896cf82ab68cafc78237f8
Fixed
ebba6f3f1b206e2b4dc4d1d5a96d18430302c2fe
Database specific
Show details 
{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "0"
                },
                {
                    "fixed":  "1.83.1"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StringRangeExpression"
        },
        {
            "range":  [
                {
                    "fixed":  "db9482836c298f234c896cf82ab68cafc78237f8"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "range":  [
                {
                    "fixed":  "ebba6f3f1b206e2b4dc4d1d5a96d18430302c2fe"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "v1.83.1",
            "range":  [
                {
                    "fixed":  "1550d9e0cddb30ce99e61a2102e8294a49461e5e"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Affected versions

1.*
1.69.3
cmd/protoc-gen-go-grpc/v1.*
cmd/protoc-gen-go-grpc/v1.0.0
cmd/protoc-gen-go-grpc/v1.0.1
cmd/protoc-gen-go-grpc/v1.1.0
cmd/protoc-gen-go-grpc/v1.2.0
cmd/protoc-gen-go-grpc/v1.3.0
cmd/protoc-gen-go-grpc/v1.4.0
cmd/protoc-gen-go-grpc/v1.5.0
cmd/protoc-gen-go-grpc/v1.5.1
cmd/protoc-gen-go-grpc/v1.6.0
cmd/protoc-gen-go-grpc/v1.6.1
cmd/protoc-gen-go-grpc/v1.6.2
gcp/observability/v1.*
gcp/observability/v1.0.0
gcp/observability/v1.0.1
security/advancedtls/v1.*
security/advancedtls/v1.0.0
stats/opencensus/v1.*
stats/opencensus/v1.0.0
v1.*
v1.0.0
v1.0.1-GA
v1.0.2
v1.0.3
v1.0.4
v1.0.5
v1.2.0
v1.27.0-pre
v1.28.0-pre
v1.29.0-dev
v1.30.0-dev
v1.30.0-dev.1
v1.31.0-dev
v1.32.0-dev
v1.33.0-dev
v1.34.0-dev
v1.35.0-dev
v1.36.0-dev
v1.37.0-dev
v1.38.0-dev
v1.39.0-dev
v1.40.0-dev
v1.41.0-dev
v1.42.0-dev
v1.43.0-dev
v1.44.0-dev
v1.45.0-dev
v1.46.0-dev
v1.47.0-dev
v1.48.0-dev
v1.49.0-dev
v1.50.0-dev
v1.51.0-dev
v1.52.0-dev
v1.53.0-dev
v1.55.0-dev
v1.56.0-dev
v1.57.0-dev
v1.58.0-dev
v1.59.0-dev
v1.60.0-dev
v1.61.0-dev
v1.65.0-dev
v1.66.0-dev
v1.67.0-dev
v1.68.0-dev
v1.69.0
v1.69.0-dev
v1.70.0-dev
v1.71.0-dev
v1.72.0-dev
v1.73.0-dev
v1.74.0-dev
v1.75.0-dev
v1.76.0-dev
v1.77.0-dev
v1.78.0-dev
v1.79.0-dev
v1.80.0-dev
v1.81.0-dev
v1.82.0-dev
v1.83.0
v1.83.0-dev
v1.84.0-dev
v1.85.0-dev

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84303.json"