KnownHosts Revocation Check Failure in golang.org/x/crypto/ssh<0.52.0
CVE-2026-42508 Published on May 22, 2026

Invoking auth bypass via unenforced @revoked status in golang.org/x/crypto/ssh/knownhosts
Previously, a revoked 'SignatureKey' belonging to a CA was not correctly checked for revocation. Now, both the 'key' and 'key.SignatureKey' are checked for @revoked.

NVD

Vulnerability Analysis

CVE-2026-42508 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.

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

Weakness Type

Improper Certificate Validation

The software does not validate, or incorrectly validates, a certificate. When a certificate is invalid or malicious, it might allow an attacker to spoof a trusted entity by interfering in the communication path between the host and client. The software might connect to a malicious host while believing it is a trusted host, or the software might be deceived into accepting spoofed data that appears to originate from a trusted host.


Products Associated with CVE-2026-42508

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-42508 are published in these products:

Canonical Ubuntu Linux
 
Red Hat Hummingbird
 
Red Hat Assisted Installer
 
Red Hat Openshift Builds
 
Red Hat External Secrets Operator
 
Red Hat Multicluster Engine
 
Red Hat Openshift Api Data Protection
 
Red Hat Serverless
 
Red Hat Acm
 
Red Hat Advanced Cluster Security
 
Red Hat Ceph Storage
 
Red Hat Edge Manager
 
Red Hat Enterprise Linux (RHEL)
 
Red Hat Enterprise Linux Ai
 
Red Hat Openshift Ai
 
Red Hat Openshift
 
Red Hat Openshift Data Foundation
 
Red Hat Devworkspace
 
Red Hat Openshift Gitops
 
Red Hat Container Native Virtualization
 
Red Hat Openstack
 
Red Hat Quay
 
Red Hat Trusted Artifact Signer
 

Affected Versions

golang.org/x/crypto/ssh/knownhosts: Red Hat Hardened Images: Assisted Installer for Red Hat OpenShift Container Platform 2: Builds for Red Hat OpenShift: External Secrets Operator for Red Hat OpenShift: Red Hat Multicluster Engine for Kubernetes: Red Hat OpenShift API for Data Protection: Red Hat OpenShift Serverless: Red Hat Advanced Cluster Management for Kubernetes 2: Red Hat Advanced Cluster Security 4: Red Hat Ceph Storage 9: Red Hat Edge Manager 1: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat Enterprise Linux AI (RHEL AI) 3: Red Hat OpenShift AI (RHOAI): 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 Virtualization 4: Red Hat OpenStack Platform 16.2: Red Hat Quay 3: Red Hat Trusted Artifact Signer: Red Hat OpenStack Platform 17.1: Red Hat OpenStack Platform 18.0:

Exploit Probability

EPSS
0.31%
Percentile
21.97%

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.