go/crypto/ssh CPU DoS via oversized RSA/DSA keys before 0.52
CVE-2026-39829 Published on May 22, 2026

Invoking pathological RSA/DSA parameters may cause DoS in golang.org/x/crypto/ssh
The RSA and DSA public key parsers did not enforce size limits on key parameters. A crafted public key with an excessively large modulus or DSA parameter could cause several minutes of CPU consumption during signature verification. This could be triggered by unauthenticated clients during public key authentication. RSA moduli are now limited to 8192 bits, and DSA parameters are validated per FIPS 186-2.

NVD

Vulnerability Analysis

CVE-2026-39829 can be exploited with network access, and does not require authorization privileges or 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 no impact on confidentiality and integrity, and a high impact on availability.

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

Weakness Type

Improper Validation of Specified Quantity in Input

The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.


Products Associated with CVE-2026-39829

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Red Hat Enterprise Linux (RHEL)
 
Red Hat Assisted Installer
 
Red Hat Openshift Builds
 
Red Hat Cert Manager
 
Red Hat Confidential Compute Attestation
 
Red Hat Cryostat
 
Red Hat External Secrets Operator
 
Red Hat Multicluster Engine
 
Red Hat Openshift Api Data Protection
 
Red Hat Openshift Pipelines
 
Red Hat Serverless
 
Red Hat Acm
 
Red Hat Advanced Cluster Security
 
Red Hat Ceph Storage
 
Red Hat Edge Manager
 
Red Hat Openshift Ai
 
Red Hat Openshift
 
Red Hat Openshift Devspaces
 
Red Hat Devworkspace
 
Red Hat Windows Machine Config
 
Red Hat Openshift Gitops
 
Red Hat Openshift Service On Aws
 
Red Hat Container Native Virtualization
 
Red Hat Openstack
 
Red Hat Quay
 
Red Hat Trusted Artifact Signer
 
Red Hat Openshift Security Profiles Operator
 
Red Hat Zero Trust Workload Identity Manager
 
Red Hat Openshift Data Foundation
 

Affected Versions

golang.org/x/crypto/ssh: Red Hat Enterprise Linux AppStream (v. 9): Assisted Installer for Red Hat OpenShift Container Platform 2: Builds for Red Hat OpenShift: cert-manager Operator for Red Hat OpenShift: Red Hat Confidential Compute Attestation: Red Hat Cryostat 4: External Secrets Operator for Red Hat OpenShift: Red Hat Multicluster Engine for Kubernetes: Red Hat OpenShift API for Data Protection: Red Hat OpenShift Pipelines: 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 OpenShift AI (RHOAI): Red Hat OpenShift Container Platform 4: Red Hat OpenShift Dev Spaces: Red Hat OpenShift Dev Workspaces Operator: Red Hat OpenShift for Windows Containers: Red Hat OpenShift GitOps: Red Hat OpenShift on AWS: Red Hat OpenShift Virtualization 4: Red Hat OpenStack Platform 16.2: Red Hat OpenStack Platform 17.1: Red Hat OpenStack Platform 18.0: Red Hat Quay 3: Red Hat Trusted Artifact Signer: Red Hat Security Profiles Operator: Red Hat Zero Trust Workload Identity Manager: Red Hat Zero Trust Workload Identity Manager - Tech Preview: Red Hat Openshift Data Foundation 4:

Exploit Probability

EPSS
0.28%
Percentile
19.16%

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.