Skip to content
Fencer Vulns
medium 6.5

CVE-2026-39827 json

Invoking memory leak when rejecting channels can lead to DoS in golang.org/x/crypto/ssh

published 2026-05-22 5 mo ago modified 2026-09-22 48 d ago also EUVD-2026-31392 , GHSA-qpw4-5x99-6vjp , GO-2026-5016

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits
0
none known

Summary

An authenticated SSH client that repeatedly opened channels which were rejected by the server caused unbounded memory growth, eventually crashing the server process and affecting all connected users. Rejected channels are now properly removed from the connection's internal state and released for garbage collection.

Patch / fix

  • go golang.org/x/crypto 0.52.0
  • golang.org/x/crypto golang.org/x/crypto/ssh 0.52.0
  • golang-go.crypto Debian 14 1:0.52.0-1

debian advisories DEBIAN-CVE-2026-39827

  • golang1.27 hummingbird 1 1.27.1-0.1.hum1
  • golang1.27-bin hummingbird 1 1.27.1-0.1.hum1
  • golang1.27-src hummingbird 1 1.27.1-0.1.hum1
  • golang1.27-misc hummingbird 1 1.27.1-0.1.hum1
  • golang1.27-tests hummingbird 1 1.27.1-0.1.hum1
  • golang1.26 hummingbird 1 1.26.8-0.1.hum1
  • golang1.26-bin hummingbird 1 1.26.8-0.1.hum1
  • golang1.26-src hummingbird 1 1.26.8-0.1.hum1

red hat advisories RHSA-2026:66561RHSA-2026:62391

  • distribution SLES 16.0, SLES for SAP applications 16.0 3.1.1-160000.3.1
  • distribution SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 3.1.1-150400.9.41.1
  • containerized-data-importer SLE Module for Containers 15 SP7 1.64.0-150700.9.14.1
  • kubevirt SLE Module for Containers 15 SP7 1.7.4-150700.3.30.1
  • terraform-provider-aws SLE Module for Public Cloud 15 SP5, SLE Module for Public Cloud 15 SP4 3.11.0-150200.6.18.1
  • terraform-provider-tls SLE Module for Public Cloud 15 SP5, SLE Module for Public Cloud 15 SP4 3.0.0-150200.5.15.1
  • terraform-provider-helm SLE Module for Public Cloud 15 SP5, SLE Module for Public Cloud 15 SP4 2.9.0-150200.6.23.1
  • terraform-provider-null SLE Module for Public Cloud 15 SP5, SLE Module for Public Cloud 15 SP4 3.0.0-150200.6.18.1

suse advisories SUSE-SU-2026:23852-1SUSE-SU-2026:23864-1SUSE-SU-2026:4212-1SUSE-SU-2026:4209-1SUSE-SU-2026:3203-1SUSE-SU-2026:3056-1

  • cloudflared openSUSE Leap 16.0 2026.9.1-bp160.1.1
  • distribution openSUSE Leap 16.0 3.1.1-160000.3.1
  • cloudflared openSUSE Tumbleweed 2026.9.1-1.1
  • kit openSUSE Tumbleweed 0.107.0-1.1
  • containerized-data-importer1.65 openSUSE Leap 16.0 1.65.0-160000.3.1
  • glab openSUSE Leap 16.0 1.114.0-bp160.1.1
  • kubevirt1.8 openSUSE Leap 16.0 1.8.4-160000.1.1
  • containerized-data-importer1.66 openSUSE Tumbleweed 1.66.0-1.1

opensuse advisories openSUSE-SU-2026:21924-1openSUSE-SU-2026:21898-1openSUSE-SU-2026:11813-1openSUSE-SU-2026:11806-1openSUSE-SU-2026:21824-1openSUSE-SU-2026:21662-1

  • cert-manager Azure Linux 3.0 1.12.15-9
  • cf-cli Azure Linux 3.0 8.7.11-7
  • docker-buildx Azure Linux 3.0 0.14.0-15
  • docker-compose Azure Linux 3.0 2.27.0-12
  • gh Azure Linux 3.0 2.62.0-17
  • kubernetes Azure Linux 3.0 1.30.10-25
  • kubevirt Azure Linux 3.0 1.7.1-7
  • moby-engine Azure Linux 3.0 25.0.3-18

azure linux advisories AZL-87411AZL-87474AZL-87636AZL-87720AZL-87765AZL-87930

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-39827 updated cvss 6.5

golang.org/x/crypto/ssh: golang: golang.org/x/crypto/ssh: Denial of Service via repeated rejected channel openings

  • Red Hat Assisted Installer for Red Hat OpenShift Container Platform 2 assisted/agent-preinstall-image-builder-rhel9 Red Hat Builds for Red Hat OpenShift openshift-builds/openshift-builds-waiters-rhel9, openshift-builds/openshift-builds-webhook-rhel9, openshift-builds/openshift-builds-controller-rhel9, openshift-builds/openshift-builds-git-cloner-rhel9, openshift-builds/openshift-builds-image-bundler-rhel9, openshift-builds/openshift-builds-image-processing-rhel9 Red Hat Confidential Compute Attestation openshift-sandboxed-containers/osc-rhel9-operator, openshift-sandboxed-containers/osc-podvm-payload-rhel9, openshift-sandboxed-containers/osc-cloud-api-adaptor-rhel9 Red Hat Cryostat 4 cryostat/cryostat-storage-rhel9, cryostat/cryostat-grafana-dashboard-rhel9 Red Hat External Secrets Operator for Red Hat OpenShift external-secrets-operator/external-secrets-rhel9 Red Hat Multicluster Engine for Kubernetes multicluster-engine/assisted-service-8-rhel8, multicluster-engine/assisted-service-9-rhel9, multicluster-engine/kube-rbac-proxy-mce-rhel9, multicluster-engine/azure-service-operator-rhel9, multicluster-engine/cluster-api-provider-azure-rhel9, multicluster-engine/cluster-image-set-controller-rhel9, +1 more
    +33 more products
    Red Hat Multicluster Global Hub multicluster-globalhub/multicluster-globalhub-grafana-rhel9 Red Hat OpenShift API for Data Protection oadp/oadp-mustgather-rhel9, oadp/oadp-velero-restic-restore-helper-rhel9 Red Hat OpenShift Pipelines openshift-pipelines-client Red Hat OpenShift Serverless openshift-serverless-clients, openshift-serverless-1/kn-plugin-func-func-util-rhel9 Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/volsync-rhel9, rhacm2/acm-grafana-rhel9, rhacm2/acm-must-gather-rhel9, rhacm2/kube-rbac-proxy-rhel9, rhacm2/observatorium-rhel9-operator, rhacm2/multicluster-operators-subscription-rhel9 Red Hat Advanced Cluster Security 4 advanced-cluster-security/rhacs-main-rhel8, advanced-cluster-security/rhacs-main-rhel9, advanced-cluster-security/rhacs-roxctl-rhel8, advanced-cluster-security/rhacs-roxctl-rhel9, advanced-cluster-security/rhacs-scanner-rhel8, advanced-cluster-security/rhacs-scanner-rhel9, +7 more Red Hat Ceph Storage 5 rhceph/rhceph-5-dashboard-rhel8 Red Hat Ceph Storage 6 rhceph/rhceph-6-dashboard-rhel9 Red Hat Ceph Storage 7 rhceph/grafana-rhel9 Red Hat Ceph Storage 8 rhceph/grafana-rhel9 Red Hat Ceph Storage 9 rhceph/alloy-rhel10, rhceph/grafana-rhel10 Red Hat Edge Manager 1 flightctl, rhem/flightctl-api-rhel9, rhem/flightctl-api-rhel10, rhem/flightctl-worker-rhel9, rhem/flightctl-worker-rhel10, rhem/flightctl-db-setup-rhel9, +19 more Red Hat Enterprise Linux 8 rhc, conmon, podman, skopeo, buildah, toolbox, +11 more Red Hat Enterprise Linux 9 rhc, conmon, podman, buildah, podman-tests, buildah-tests, +7 more Red Hat Enterprise Linux 10 podman, buildah, trustee, gvisor-tap-vsock Red Hat Hardened Images golang1.25 Red Hat OpenShift AI (RHOAI) rhoai/odh-trainer-rhel9, rhoai/odh-model-registry-rhel9, rhoai/odh-data-science-pipelines-argo-argoexec-rhel9, rhoai/odh-data-science-pipelines-argo-workflowcontroller-rhel9 Red Hat OpenShift Container Platform 4 cri-o, conmon, podman, openshift, microshift, podman-tests, +124 more Red Hat OpenShift Container Platform 5 cri-o, openshift, microshift, openshift5/ose-ptp-rhel9, openshift5/ose-tests-rhel9, openshift5/ose-dpu-cni-rhel9, +40 more Red Hat OpenShift Dev Spaces devspaces/traefik-rhel9, devspaces/configbump-rhel9 Red Hat OpenShift Dev Workspaces Operator devworkspace/devworkspace-rhel9-operator, devworkspace/devworkspace-project-clone-rhel9 Red Hat OpenShift for Windows Containers openshift4-wincw/windows-machine-config-rhel9-operator, openshift4-wincw/windows-machine-config-operator-bundle Red Hat OpenShift GitOps openshift-gitops-1/argocd-rhel8, openshift-gitops-1/argocd-rhel9, openshift-gitops-1/gitops-rhel8, openshift-gitops-1/gitops-rhel9, openshift-gitops-1/argocd-agent-rhel8, openshift-gitops-1/argocd-agent-rhel9, +4 more Red Hat OpenShift on AWS rosa Red Hat OpenShift Virtualization 4 kubevirt Red Hat OpenStack Platform 16.2 etcd, rhosp-rhel8/osp-director-agent, rhosp-rhel8/osp-director-operator, rhosp-rhel8/osp-director-operator-bundle Red Hat OpenStack Platform 17.1 rhosp-rhel9/osp-director-agent, rhosp-rhel9/osp-director-operator, rhosp-rhel9/osp-director-operator-bundle Red Hat OpenStack Platform 18.0 rhoso-operators/octavia-rhel9-operator, rhoso-operators/prometheus-podman-exporter-rhel9 Red Hat Quay 3 quay/quay-builder-rhel8, quay/quay-builder-rhel9 Red Hat Trusted Artifact Signer rhtas/ec-rhel9, rhtas/cosign-rhel9, rhtas/fulcio-rhel9, rhtas/gitsign-rhel9, rhtas/rekor-cli-rhel9, rhtas/rekor-server-rhel9, +10 more Red Hat Security Profiles Operator compliance/openshift-security-profiles-rhel8-operator, compliance/openshift-security-profiles-operator-bundle Red Hat Zero Trust Workload Identity Manager zero-trust-workload-identity-manager/spiffe-spire-agent-rhel9, zero-trust-workload-identity-manager/spiffe-spire-server-rhel9, zero-trust-workload-identity-manager/spiffe-spire-oidc-discovery-provider-rhel9 Red Hat Zero Trust Workload Identity Manager - Tech Preview zero-trust-workload-identity-manager/spiffe-spire-agent-rhel9, zero-trust-workload-identity-manager/spiffe-spire-server-rhel9, zero-trust-workload-identity-manager/spiffe-spire-oidc-discovery-provider-rhel9
    affected: no fix available “Fix deferred”
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.17 cert-manager/cert-manager-operator-rhel9 1791788287, cert-manager/jetstack-cert-manager-rhel9 1791371069, cert-manager/jetstack-cert-manager-acmesolver-rhel9 1791371080
    fixed: vendor fix RHSA-2026:82322

4 more fixed, 3 more not affected in the full advisory

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
go golang.org/x/crypto
<0.52.0
0.52.0

Affected products

  • golang.org/x/crypto golang.org/x/crypto/ssh

Classification

Weakness
  • CWE-924 Improper Enforcement of Message Integrity During Transmission in a Communication Channel

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.