CVE-2026-33186Network attack vector

Authorization bypass via noncanonical HTTP/2 path

Published Mar 20, 2026 · Updated Aug 28, 2026

Improper path validation in gRPC-Go before 1.79.3 allows remote attackers to bypass path-based authorization with malformed HTTP/2 requests. The server routes a :path lacking its required leading slash while authorization interceptors evaluate the raw noncanonical value, so canonical deny rules do not match. Exploitation requires direct HTTP/2 access, path-based authorization, canonical deny rules, and a fallback allow rule; protected RPC methods can then be invoked.

CVSS severity9.1
Critical
EPSS probability1.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper path validation in gRPC-Go before 1.79.3 allows remote attackers to bypass path-based authorization with malformed HTTP/2 requests. The server routes a :path lacking its required leading slash while authorization interceptors evaluate the raw noncanonical value, so canonical deny rules do not match. Exploitation requires direct HTTP/2 access, path-based authorization, canonical deny rules, and a fallback allow rule; protected RPC methods can then be invoked.

The record

CVE
CVE-2026-33186
Published
Mar 20, 2026
Updated
Aug 28, 2026
Vendor
389 Directory Server
Product
Assisted Installer for OpenShift Container Platform
Classifications
CWE-285, CWE-551, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

389 Directory Server · Assisted Installer for OpenShift Container PlatformAffected versions are unavailable in this record.
389 Directory Server · Red Hat QuayAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift ServerlessAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Distributed TracingAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Service MeshAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift LightspeedAffected versions are unavailable in this record.
389 Directory Server · cert-manager Operator for Red Hat OpenShiftAffected versions are unavailable in this record.
389 Directory Server · OpenShift Secondary Scheduler OperatorAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift AIAffected versions are unavailable in this record.
389 Directory Server · OpenShift API for Data ProtectionAffected versions are unavailable in this record.
389 Directory Server · Red Hat Edge ManagerAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Dev SpacesAffected versions are unavailable in this record.
389 Directory Server · Dynamic Accelerator Slicer OperatorAffected versions are unavailable in this record.
389 Directory Server · OpenShift Developer Tools and ServicesAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Data Foundation 4.16Affected versions are unavailable in this record.
389 Directory Server · Job SetAffected versions are unavailable in this record.
389 Directory Server · Self Node Remediation OperatorAffected versions are unavailable in this record.
389 Directory Server · Red Hat Developer HubAffected versions are unavailable in this record.
389 Directory Server · Red Hat Container Native Virtualization 4.20Affected versions are unavailable in this record.
389 Directory Server · Security Profiles OperatorAffected versions are unavailable in this record.
gRPC · gRPC-Goversion=< 1.79.3
389 Directory Server · Red Hat Enterprise Linux AIAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Data FoundationAffected versions are unavailable in this record.
389 Directory Server · multicluster engine for Kubernetes 2.6Affected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Container Platform 4.21Affected versions are unavailable in this record.
389 Directory Server · Zero Trust Workload Identity Manager - Tech PreviewAffected versions are unavailable in this record.
389 Directory Server · Red Hat Advanced Cluster Management for KubernetesAffected versions are unavailable in this record.
389 Directory Server · Kube Descheduler OperatorAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift BuildsAffected versions are unavailable in this record.
389 Directory Server · Red Hat Advanced Cluster Security for KubernetesAffected versions are unavailable in this record.
389 Directory Server · Multicluster Global HubAffected versions are unavailable in this record.
389 Directory Server · Leader Worker SetAffected versions are unavailable in this record.
389 Directory Server · ExternalDNS OperatorAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Container Platform 4.18Affected versions are unavailable in this record.
389 Directory Server · Red Hat Migration Toolkit for ContainersAffected versions are unavailable in this record.
389 Directory Server · multicluster engine for Kubernetes 2.10Affected versions are unavailable in this record.
389 Directory Server · OpenShift Run Once Duration Override OperatorAffected versions are unavailable in this record.
389 Directory Server · Network Observability OperatorAffected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 9.4 Update Services for SAP SolutionsAffected versions are unavailable in this record.
389 Directory Server · Red Hat Ansible Automation PlatformAffected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 10Affected versions are unavailable in this record.
389 Directory Server · DevWorkspace OperatorAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Container Platform 4.15Affected versions are unavailable in this record.
389 Directory Server · Migration Toolkit for ContainersAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift VirtualizationAffected versions are unavailable in this record.
389 Directory Server · File Integrity OperatorAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Container Platform 4.19Affected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Compliance Operator 1Affected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 7Affected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 9.4 Extended Update SupportAffected versions are unavailable in this record.
389 Directory Server · Logical Volume Manager StorageAffected versions are unavailable in this record.
389 Directory Server · Kernel Module Management OperatorAffected versions are unavailable in this record.
389 Directory Server · Workload Availability for Red Hat OpenShiftAffected versions are unavailable in this record.
389 Directory Server · Migration Toolkit for VirtualizationAffected versions are unavailable in this record.
389 Directory Server · Red Hat Connectivity LinkAffected versions are unavailable in this record.
389 Directory Server · Red Hat build of Podman DesktopAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Container Platform 4.22Affected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Container Platform 4.13Affected versions are unavailable in this record.
389 Directory Server · Red Hat OpenStack PlatformAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift GitOpsAffected versions are unavailable in this record.
389 Directory Server · multicluster engine for Kubernetes 2.8Affected versions are unavailable in this record.
389 Directory Server · Gatekeeper 3Affected versions are unavailable in this record.
389 Directory Server · Red Hat Certification Program for Red Hat Enterprise Linux 9Affected versions are unavailable in this record.
389 Directory Server · Deployment Validation OperatorAffected versions are unavailable in this record.
389 Directory Server · Storage-Based Remediation OperatorAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Container Platform 4.12Affected versions are unavailable in this record.
389 Directory Server · Red Hat Container Native Virtualization 4.18Affected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift LoggingAffected versions are unavailable in this record.
389 Directory Server · Red Hat Web TerminalAffected versions are unavailable in this record.
389 Directory Server · Red Hat Build of Podman Desktop - Tech PreviewAffected versions are unavailable in this record.
389 Directory Server · Red Hat SatelliteAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Container PlatformAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Cluster Manager CLIAffected versions are unavailable in this record.
389 Directory Server · Red Hat build of CryostatAffected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.
389 Directory Server · multicluster engine for Kubernetes 2.9Affected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift PipelinesAffected versions are unavailable in this record.
389 Directory Server · Red Hat Lightspeed for RuntimesAffected versions are unavailable in this record.
389 Directory Server · multicluster engine for KubernetesAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Container Platform 4Affected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 7 Extended Lifecycle SupportAffected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 10.0 Extended Update SupportAffected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 9.6 Extended Update SupportAffected versions are unavailable in this record.
389 Directory Server · Red Hat Trusted Artifact SignerAffected versions are unavailable in this record.
389 Directory Server · Red Hat Container Native Virtualization 4.22Affected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 8Affected versions are unavailable in this record.
389 Directory Server · Red Hat Container Native VirtualizationAffected versions are unavailable in this record.
389 Directory Server · Logging Subsystem for Red Hat OpenShiftAffected versions are unavailable in this record.
389 Directory Server · Red Hat AI Inference ServerAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Container Platform 4.20Affected versions are unavailable in this record.

Published CVSS scores

9.1GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
9.1Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-285Improper Authorization
CWE-551Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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