Go 1.26.x crypto/x509 DNS Constraint Case Sensitivity
CVE-2026-33810 Published on April 8, 2026

Case-sensitive excludedSubtrees name constraints cause Auth Bypass in crypto/x509
When verifying a certificate chain containing excluded DNS constraints, these constraints are not correctly applied to wildcard DNS SANs which use a different case than the constraint. This only affects validation of otherwise trusted certificate chains, issued by a root CA in the VerifyOptions.Roots CertPool, or in the system certificate pool.

NVD

Vulnerability Analysis

CVE-2026-33810 is exploitable with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
REQUIRED
Scope:
CHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
LOW
Availability Impact:
LOW

Weakness Type

Improper Validation of Unsafe Equivalence in Input

The product receives an input value that is used as a resource identifier or other type of reference, but it does not validate or incorrectly validates that the input is equivalent to a potentially-unsafe value.


Products Associated with CVE-2026-33810

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Affected Versions

Go standard library crypto/x509: Red Hat Cryostat 4 on RHEL 9: Red Hat OpenStack Platform 17.1: Red Hat Enterprise Linux AppStream EUS (v. 10.0): Red Hat Enterprise Linux AppStream (v. 10): Red Hat Enterprise Linux AppStream EUS (v.9.4): Red Hat Enterprise Linux AppStream EUS (v.9.6): Red Hat Enterprise Linux AppStream (v. 9): Red Hat HawtIO HawtIO 4.4.0: Logging Subsystem for Red Hat OpenShift 6.0: Logging Subsystem for Red Hat OpenShift 6.4: Red Hat Multicluster Global Hub 1.4.5: Red Hat Multicluster Global Hub 1.5.4: Red Hat Multicluster Global Hub 1.6.2: Red Hat OpenShift API for Data Protection 1.4: Red Hat OpenShift API for Data Protection 1.5: Red Hat OpenShift Compliance Operator 1: Red Hat Ansible Automation Platform 2.6: Red Hat Hardened Images: Red Hat Lightspeed (formerly Insights) for Runtimes 1: Red Hat OpenShift Builds 1.6.5: Red Hat OpenShift Builds 1.7.3: Red Hat OpenShift Dev Spaces 3.28: Red Hat OpenShift distributed tracing 3.9.3: Red Hat Trusted Artifact Signer 1.3: Red Hat Web Terminal 1.11: Red Hat Web Terminal 1.12: Red Hat Web Terminal 1.13: Red Hat Web Terminal 1.14: Red Hat Web Terminal 1.15: Assisted Installer for Red Hat OpenShift Container Platform 2: cert-manager Operator for Red Hat OpenShift: Red Hat Confidential Compute Attestation: Red Hat Deployment Validation Operator: Red Hat Fence Agents Remediation Operator: Red Hat File Integrity Operator: Red Hat Gatekeeper 3: Logging Subsystem for Red Hat OpenShift: Red Hat Machine Deletion Remediation Operator: Red Hat Migration Toolkit for Applications 8: Red Hat Migration Toolkit for Containers: mirror registry for Red Hat OpenShift: Red Hat Multicluster Engine for Kubernetes: Red Hat OpenShift Developer Tools and Services: Red Hat OpenShift Pipelines: Red Hat OpenShift Serverless: Red Hat 3scale API Management Platform 2: Red Hat Certification Program for Red Hat Enterprise Linux 9: Red Hat Connectivity Link 1: Red Hat Edge Manager 1: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 7: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat Enterprise Linux AI (RHEL AI) 3: Red Hat OpenShift Cluster Manager CLI: Red Hat OpenShift Container Platform 4: Red Hat Openshift Data Foundation 4: Red Hat OpenShift Dev Workspaces Operator: Red Hat OpenShift GitOps: Red Hat OpenShift on AWS: Red Hat OpenShift Virtualization 4: Red Hat OpenStack Platform 16.2: Red Hat OpenStack Platform 18.0: Red Hat Quay 3: Red Hat Satellite 6: Red Hat Security Profiles Operator: Custom Metric Autoscaler operator for Red Hat Openshift: External Secrets Operator for Red Hat OpenShift: Red Hat ExternalDNS Operator: Red Hat Logical Volume Manager Storage: mirror registry for Red Hat OpenShift 2: Red Hat Network Observability Operator: Red Hat Node HealthCheck Operator: Red Hat OpenShift Lightspeed: Red Hat OpenShift Service Mesh 2: Red Hat OpenShift Service Mesh 3: Power monitoring for Red Hat OpenShift: Red Hat Advanced Cluster Management for Kubernetes 2: Red Hat Advanced Cluster Security 4: Red Hat Ansible Automation Platform 2: Red Hat Developer Hub: Red Hat OpenShift AI (RHOAI): Red Hat OpenShift for Windows Containers: Red Hat Service Interconnect 1: Red Hat Service Interconnect 2: Red Hat Service Telemetry Framework 1.5: Red Hat streams for Apache Kafka 3: Red Hat Zero Trust Workload Identity Manager: Red Hat Zero Trust Workload Identity Manager - Tech Preview:

Exploit Probability

EPSS
0.26%
Percentile
17.32%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.