{"id":"CVE-2026-39834","title":"golang.org/x/crypto/ssh: golang: golang.org/x/crypto/ssh: Denial of Service due to integer overflow in SSH channel write (CVE-2026-39834)","summary":"A flaw was found in golang.org/x/crypto/ssh. When a remote attacker attempts to write data larger than 4GB in a single call on an SSH (Secure Shell) channel, an integer overflow occurs in the internal payload size calculation. This vulnera…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":"CWE-190","vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 4","affected":["builds_for_red_hat_openshift","cryostat 4","openshift_pipelines","openshift_serverless","ceph_storage 5","ceph_storage 6","ceph_storage 7","ceph_storage 8","ceph_storage 9","hardened_images","openshift_dev_spaces","openshift_dev_workspaces_operator","trusted_artifact_signer","assisted_installer_for_red_hat_openshift_container_platform 2","cert_manager_operator_for_red_hat_openshift","confidential_compute_attestation","external_secrets_operator_for_red_hat_openshift","multicluster_engine_for_kubernetes","multicluster_global_hub","openshift_api_for_data_protection","openshift_service_mesh 2","advanced_cluster_management_for_kubernetes 2","advanced_cluster_security 4","edge_manager 1","enterprise_linux 10","enterprise_linux 8","enterprise_linux 9","openshift_ai_rhoai","openshift_container_platform 4","openshift_for_windows_containers","openshift_gitops","openshift_on_aws","openshift_virtualization 4","openstack_platform 16.2","openstack_platform 17.1","openstack_platform 18.0","quay 3","security_profiles_operator","zero_trust_workload_identity_manager","zero_trust_workload_identity_manager_tech_preview"],"patched":["openshift_api_for_data_protection 1.6","hardened_images","openshift_data_foundation 4.22","multicluster_engine_for_kubernetes 2.11"],"published":"2026-05-22","updated":"2026-09-21","sourceUpdated":"2026-09-21T11:38:14+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39834.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39834.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-39834"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2480676"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-39834"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39834"},{"url":"https://go.dev/cl/781663"},{"url":"https://go.dev/issue/79567"},{"url":"https://groups.google.com/g/golang-announce/c/a082jnz-LvI"},{"url":"https://pkg.go.dev/vuln/GO-2026-5020"},{"url":"https://access.redhat.com/errata/RHSA-2026:43692"},{"url":"https://access.redhat.com/errata/RHSA-2026:62391"},{"url":"https://access.redhat.com/errata/RHSA-2026:66561"},{"url":"https://access.redhat.com/errata/RHSA-2026:37387"},{"url":"https://access.redhat.com/errata/RHSA-2026:57194"},{"url":"https://github.com/advisories/GHSA-rm3j-f69w-wqmq"}],"tags":["csaf","vex","red-hat","ghsa","go","score-dispute"],"epss":0.00525,"epssPercentile":0.43476,"ecosystem":"go","scores":{"vendor":6.5,"ghsa":9.1},"ingestedAt":"2026-06-26T16:43:14.192Z","slug":"CVE-2026-39834","body":"## Overview\n\nA flaw was found in golang.org/x/crypto/ssh. When a remote attacker attempts to write data larger than 4GB in a single call on an SSH (Secure Shell) channel, an integer overflow occurs in the internal payload size calculation. This vulnerability causes the write loop to spin indefinitely, continuously sending empty packets without making progress. The primary consequence is a denial of service (DoS), as the affected system consumes resources and prevents legitimate data transfer.\n\n## Vendor advisories\n\n- **RHSA-2026:43692** · Red Hat · fixed in: OpenShift API for Data Protection 1.6 · released 2026-07-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:43692)\n- **RHSA-2026:62391** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-02 · [advisory](https://access.redhat.com/errata/RHSA-2026:62391)\n- **RHSA-2026:66561** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-11 · [advisory](https://access.redhat.com/errata/RHSA-2026:66561)\n- **RHSA-2026:37387** · Red Hat · fixed in: Red Hat Openshift Data Foundation 4.22 · released 2026-07-09 · [advisory](https://access.redhat.com/errata/RHSA-2026:37387)\n- **RHSA-2026:57194** · Red Hat · fixed in: multicluster engine for Kubernetes 2.11 · released 2026-08-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:57194)\n- **Red Hat VEX** · Moderate · affected: Builds for Red Hat OpenShift, Cryostat 4, OpenShift Pipelines, OpenShift Serverless, Red Hat Ceph Storage 5, Red Hat Ceph Storage 6, … · no fix planned: Red Hat Hardened Images, Builds for Red Hat OpenShift, Cryostat 4, OpenShift Pipelines, … · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39834.json)\n\n**golang.org/x/crypto/ssh: golang: golang.org/x/crypto/ssh: Denial of Service due to integer overflow in SSH channel write** — rated Moderate by Red Hat. Released 2026-05-22, updated 2026-09-21.\n\nAffected:\n\n- Builds for Red Hat OpenShift\n- Cryostat 4\n- OpenShift Pipelines\n- OpenShift Serverless\n- Red Hat Ceph Storage 5\n- Red Hat Ceph Storage 6\n- Red Hat Ceph Storage 7\n- Red Hat Ceph Storage 8\n- Red Hat Ceph Storage 9\n- Red Hat Hardened Images\n- Red Hat OpenShift Dev Spaces\n- Red Hat OpenShift Dev Workspaces Operator\n- Red Hat Trusted Artifact Signer\n- Assisted Installer for Red Hat OpenShift Container Platform 2\n- cert-manager Operator for Red Hat OpenShift\n- Confidential Compute Attestation\n- External Secrets Operator for Red Hat OpenShift\n- Multicluster Engine for Kubernetes\n- Multicluster Global Hub\n- OpenShift API for Data Protection\n- OpenShift Service Mesh 2\n- Red Hat Advanced Cluster Management for Kubernetes 2\n- Red Hat Advanced Cluster Security 4\n- Red Hat Edge Manager 1\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift AI (RHOAI)\n- Red Hat OpenShift Container Platform 4\n- Red Hat OpenShift for Windows Containers\n- Red Hat OpenShift GitOps\n- Red Hat OpenShift on AWS\n- Red Hat OpenShift Virtualization 4\n- Red Hat OpenStack Platform 16.2\n- Red Hat OpenStack Platform 17.1\n- Red Hat OpenStack Platform 18.0\n- Red Hat Quay 3\n- Security Profiles Operator\n- Zero Trust Workload Identity Manager\n- Zero Trust Workload Identity Manager - Tech Preview\n\nFixed:\n\n- OpenShift API for Data Protection 1.6\n- Red Hat Hardened Images\n- Red Hat Openshift Data Foundation 4.22\n- multicluster engine for Kubernetes 2.11\n\nNo fix planned:\n\n- Red Hat Hardened Images\n- Builds for Red Hat OpenShift\n- Cryostat 4\n- OpenShift Pipelines\n- OpenShift Serverless\n- Red Hat Ceph Storage 5\n- Red Hat Ceph Storage 6\n- Red Hat Ceph Storage 7\n- Red Hat Ceph Storage 8\n- Red Hat Ceph Storage 9\n- Red Hat OpenShift Dev Spaces\n- Red Hat OpenShift Dev Workspaces Operator\n- Red Hat Trusted Artifact Signer\n\nNot affected:\n\n- OpenShift API for Data Protection 1.6\n- Red Hat Openshift Data Foundation 4.22\n- multicluster engine for Kubernetes 2.11\n- Red Hat OpenShift Dev Spaces\n- Red Hat Trusted Artifact Signer\n\n## Remediation\n\nBefore applying this update, make sure all previously released errata\nrelevant to your system have been applied. https://access.redhat.com/errata/RHSA-2026:43692\nFor details on how to apply this update, which includes the changes described in this advisory, refer to:\nhttps://images.redhat.com/ https://access.redhat.com/errata/RHSA-2026:62391\nFor details on how to apply this update, which includes the changes described in this advisory, refer to:\nhttps://images.redhat.com/ https://access.redhat.com/errata/RHSA-2026:66561\n\n## Package advisory (CVE-2026-39834)\n\nAffected packages:\n\n- `golang.org/x/crypto/ssh < 0.52.0`\n\nPatched in:\n\n- `golang.org/x/crypto/ssh 0.52.0`\n\nSource: https://github.com/advisories/GHSA-rm3j-f69w-wqmq","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":207000,"id":"CVE-2026-39834","ts":1789749736397,"field":"cvss","old":"9.1","new":"6.5"},{"seq":206999,"id":"CVE-2026-39834","ts":1789749736397,"field":"severity","old":"critical","new":"medium"}]}