CVE-2026-33810Network attack vectorHinoki check available

Certificate validation bypass via case-sensitive wildcard constraints

Published Apr 8, 2026 · Updated Aug 28, 2026

Certificate validation bypass in Go crypto/x509 1.26.0-0 through 1.26.1 allows remote attackers to evade excluded DNS constraints. The dnsConstraints.query path compares wildcard DNS SANs against excluded subtrees without consistently normalizing letter case, so equivalent names can evade exclusion. Exploitation requires an otherwise trusted chain issued by a root in VerifyOptions.Roots or the system pool; acceptance can authenticate an excluded DNS identity.

CVSS severity8.2
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Certificate validation bypass in Go crypto/x509 1.26.0-0 through 1.26.1 allows remote attackers to evade excluded DNS constraints. The dnsConstraints.query path compares wildcard DNS SANs against excluded subtrees without consistently normalizing letter case, so equivalent names can evade exclusion. Exploitation requires an otherwise trusted chain issued by a root in VerifyOptions.Roots or the system pool; acceptance can authenticate an excluded DNS identity.

The record

CVE
CVE-2026-33810
Published
Apr 8, 2026
Updated
Aug 28, 2026
Vendor
389 Directory Server
Product
Assisted Installer for OpenShift Container Platform
Classifications
CWE-1289
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 8, 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 · Machine Deletion Remediation OperatorAffected 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 Service InterconnectAffected 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 · 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 · Mirror Registry for Red Hat OpenShiftAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Compliance OperatorAffected 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 · Red Hat build of HawtIOAffected versions are unavailable in this record.
389 Directory Server · OpenShift Developer Tools and ServicesAffected versions are unavailable in this record.
389 Directory Server · Security Profiles OperatorAffected versions are unavailable in this record.
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.
Go · crypto/x509version=1.26.0-0 <1.26.2
389 Directory Server · Node Healthcheck OperatorAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift BuildsAffected versions are unavailable in this record.
389 Directory Server · Multicluster Global HubAffected versions are unavailable in this record.
389 Directory Server · Red Hat Migration Toolkit for ContainersAffected versions are unavailable in this record.
389 Directory Server · Fence Agents Remediation 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 · 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 Enterprise Linux 7Affected versions are unavailable in this record.
389 Directory Server · Red Hat Hardened ImagesAffected 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 · Red Hat Connectivity LinkAffected 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 · Confidential Compute Attestation OperatorAffected 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 · Red Hat 3scale API ManagementAffected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportAffected 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 SatelliteAffected versions are unavailable in this record.
389 Directory Server · Red Hat OpenStack Services on OpenShiftAffected 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 · 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 Enterprise Linux 8.6 Extended Update Support Long-Life Add-OnAffected 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 OpenShift Dev Workspaces OperatorAffected 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 Enterprise Linux 8Affected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Service on AWSAffected versions are unavailable in this record.
389 Directory Server · Logging Subsystem for Red Hat OpenShiftAffected versions are unavailable in this record.

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
8.8Red Hat Product SecurityCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:L
8.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/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-1289Improper Validation of Unsafe Equivalence in Input

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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