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Fencer Vulns
critical 9.1

CVE-2026-39833 json

Invoking key constraints not enforced in golang.org/x/crypto/ssh/agent

published 2026-05-22 5 mo ago modified 2026-09-10 1 mo ago also EUVD-2026-31389 , GHSA-jppx-rxg9-jmrx , GO-2026-5005

cvss
9.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits
0
none known

Summary

The in-memory keyring returned by NewKeyring() silently accepted keys with the ConfirmBeforeUse constraint but never enforced it. The key would sign without any confirmation prompt, with no indication to the caller that the constraint was not in effect. NewKeyring() now returns an error when unsupported constraints are requested.

Patch / fix

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

debian advisories DEBIAN-CVE-2026-39833

  • lxd Ubuntu Pro 16.04 LTS 2.0.11-0ubuntu1~16.04.4+esm3
  • lxd Ubuntu Pro 18.04 LTS 3.0.3-0ubuntu1~18.04.2+esm3
  • golang-go.crypto Ubuntu Pro 16.04 LTS 1:0.0~git20151201.0.7b85b09-2ubuntu0.1~esm2
  • golang-go.crypto Ubuntu Pro 18.04 LTS 1:0.0~git20170629.0.5ef0053-2ubuntu0.1~esm2
  • golang-go.crypto Ubuntu Pro 20.04 LTS 1:0.0~git20200221.2aa609c-1ubuntu0.1~esm2
  • golang-go.crypto Ubuntu Pro 22.04 LTS 1:0.0~git20211202.5770296-1ubuntu0.1~esm2
  • golang-go.crypto Ubuntu Pro 24.04 LTS 1:0.19.0-1ubuntu0.1~esm2
  • golang-go.crypto Ubuntu Pro 26.04 LTS 1:0.47.0-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2026-39833

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • 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
  • govulncheck-vulndb SLES for SAP applications 16.0, SLES 16.0 0.0.20260827T195228-160000.1.1
  • 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-2026:4212-1SUSE-SU-2026:4209-1SUSE-SU-2026:23625-1SUSE-SU-2026:3203-1SUSE-SU-2026:3056-1SUSE-SU-2026:22613-1

  • cloudflared openSUSE Leap 16.0 2026.9.1-bp160.1.1
  • containerized-data-importer1.65 openSUSE Leap 16.0 1.65.0-160000.3.1
  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260827T195228-160000.1.1
  • glab openSUSE Leap 16.0 1.114.0-bp160.1.1
  • kubevirt1.8 openSUSE Leap 16.0 1.8.4-160000.1.1
  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
  • rclone openSUSE Leap 16.0 1.74.4-bp160.1.1
  • cosign openSUSE Leap 16.0 3.1.1-160000.1.1

opensuse advisories openSUSE-SU-2026:21924-1openSUSE-SU-2026:21824-1openSUSE-SU-2026:21761-1openSUSE-SU-2026:21662-1openSUSE-SU-2026:21590-1openSUSE-SU-2026:21483-1

  • docker-buildx Azure Linux 3.0 0.14.0-15
  • docker-compose Azure Linux 3.0 2.27.0-16
  • packer Azure Linux 3.0 1.9.5-16
  • telegraf Azure Linux 3.0 1.31.0-33

azure linux advisories AZL-87660AZL-87684AZL-88224AZL-88326

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-2026-39833 updated cvss 5.5

golang.org/x/crypto/ssh/agent: golang.org/x/crypto/ssh/agent: Security bypass due to unenforced key confirmation

  • Red Hat Assisted Installer for Red Hat OpenShift Container Platform 2 rhai/assisted-installer-agent-rhel9, assisted/agent-preinstall-image-builder-rhel9 Red Hat cert-manager Operator for Red Hat OpenShift cert-manager/cert-manager-istio-csr-rhel9, cert-manager/cert-manager-trust-manager-rhel9 Red Hat Confidential Compute Attestation openshift-sandboxed-containers/osc-rhel9-operator, openshift-sandboxed-containers/osc-must-gather-rhel9, 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 Custom Metric Autoscaler operator for Red Hat Openshift custom-metrics-autoscaler/custom-metrics-autoscaler-rhel9, custom-metrics-autoscaler/custom-metrics-autoscaler-adapter-rhel9, custom-metrics-autoscaler/custom-metrics-autoscaler-rhel9-operator, custom-metrics-autoscaler/custom-metrics-autoscaler-admission-webhooks-rhel9 Red Hat Deployment Validation Operator dvo/deployment-validation-rhel8-operator
    +21 more products
    Red Hat Exploit Intelligence exploit-intelligence-tech-preview/agent-client-rhel9, exploit-intelligence-tech-preview/vulnerability-analysis-rhel9 Red Hat External Secrets Operator for Red Hat OpenShift external-secrets-operator/external-secrets-rhel9, external-secrets-operator/bitwarden-sdk-server-rhel9, external-secrets-operator/external-secrets-operator-rhel9, external-secrets-operator/external-secrets-operator-bundle Red Hat ExternalDNS Operator edo/external-dns-rhel8, edo/external-dns-rhel9, edo/external-dns-rhel8-operator Red Hat File Integrity Operator compliance/openshift-compliance-openscap-rhel8, compliance/openshift-compliance-rhel8-operator, compliance/openshift-compliance-operator-bundle, compliance/openshift-compliance-must-gather-rhel8, compliance/openshift-file-integrity-rhel8-operator, compliance/openshift-file-integrity-operator-bundle Red Hat Gatekeeper 3 gatekeeper/gatekeeper-rhel9 Red Hat Job Set 1 job-set/jobset-rhel9-operator Red Hat Job Set Tech Preview job-set/jobset-rhel9-operator, job-set/jobset-operator-bundle Red Hat Kernel Module Management Operator for Red Hat Openshift kmm/kernel-module-management-must-gather-rhel9 Red Hat Kube Descheduler Operator kube-descheduler-operator/descheduler-rhel9, kube-descheduler-operator/kube-descheduler-rhel9-operator Red Hat Leader Worker Set leader-worker-set/lws-rhel9-operator, leader-worker-set/lws-operator-bundle Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/eventrouter-rhel9, openshift-logging/logging-loki-rhel9, openshift-logging/loki-rhel9-operator, openshift-logging/lokistack-gateway-rhel9, openshift-logging/cluster-logging-rhel9-operator Red Hat Logical Volume Manager Storage lvms4/topolvm-rhel9, lvms4/lvms-rhel8-operator, lvms4/lvms-rhel9-operator, lvms4/lvms-operator-bundle, lvms4/lvms-must-gather-rhel8, lvms4/lvms-must-gather-rhel9 Red Hat MCP Server for Red Hat OpenShift openshift-mcp-beta/openshift-mcp-server-rhel9 Red Hat Migration Toolkit for Applications 8 mta/mta-cli-rhel9, mta/mta-hub-rhel8, mta/mta-hub-rhel9, mta/mta-analyzer-addon-rhel9, mta/mta-platform-addon-rhel9, mta/mta-discovery-addon-rhel9 Red Hat Migration Toolkit for Containers rhmtc/openshift-migration-registry-rhel8, rhmtc/openshift-migration-controller-rhel8, rhmtc/openshift-migration-log-reader-rhel8, rhmtc/openshift-migration-must-gather-rhel8 Red Hat Migration Toolkit for Virtualization mtv-candidate/mtv-api-rhel9, mtv-candidate/mtv-rhel9-operator, mtv-candidate/mtv-virt-v2v-rhel9, mtv-candidate/mtv-operator-bundle, mtv-candidate/mtv-controller-rhel9, mtv-candidate/mtv-validation-rhel9, +19 more Red Hat Multiarch Tuning Operator multiarch-tuning/multiarch-tuning-rhel9-operator, multiarch-tuning/multiarch-tuning-operator-bundle Red Hat Multicluster Engine for Kubernetes multicluster-engine/hive-rhel9, multicluster-engine/work-rhel9, multicluster-engine/maestro-rhel9, multicluster-engine/discovery-rhel9, multicluster-engine/placement-rhel9, multicluster-engine/must-gather-rhel9, +18 more Red Hat Multicluster Global Hub multicluster-globalhub/multicluster-globalhub-agent-rhel9, multicluster-globalhub/multicluster-globalhub-grafana-rhel9, multicluster-globalhub/multicluster-globalhub-manager-rhel9, multicluster-globalhub/multicluster-globalhub-rhel9-operator, multicluster-globalhub/multicluster-globalhub-postgres-exporter-rhel9 Red Hat Network Observability Operator network-observability/network-observability-ebpf-agent-rhel9, network-observability/network-observability-flowlogs-pipeline-rhel9 Red Hat Node HealthCheck Operator workload-availability/node-healthcheck-must-gather-rhel9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat OpenShift API for Data Protection oadp/oadp-velero-plugin-for-csi-rhel9
    affected: workaround, no fix available
  • Red Hat OpenShift Developer Tools and Services ocp-tools-4/jenkins-rhel8, ocp-tools-4/jenkins-rhel9, ocp-tools-4/jenkins-agent-base-rhel8, ocp-tools-4/jenkins-agent-base-rhel9 Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-agentic-sandbox-rhel9 Red Hat OpenShift Pipelines openshift-pipelines-client, openshift-pipelines/pipelines-opc-rhel9, openshift-pipelines/pipelines-cache-rhel9, openshift-pipelines/pipelines-cli-tkn-rhel8, openshift-pipelines/pipelines-cli-tkn-rhel9, openshift-pipelines/pipelines-hub-api-rhel8, +24 more Red Hat OpenShift Run Once Duration Override Operator run-once-duration-override-operator/run-once-duration-override-rhel9, run-once-duration-override-operator/run-once-duration-override-rhel9-operator Red Hat OpenShift Secondary Scheduler Operator openshift-secondary-scheduler-operator/secondary-scheduler-rhel9-operator Red Hat OpenShift Serverless openshift-serverless-clients, openshift-serverless-1/kn-client-kn-rhel9, openshift-serverless-1/logic-rhel9-operator, openshift-serverless-1/kn-ekb-receiver-rhel9, openshift-serverless-1/kn-ekb-dispatcher-rhel9, openshift-serverless-1/kn-eventing-filter-rhel9, +16 more
    +6 more products
    Red Hat OpenShift Service Mesh 2 openshift-service-mesh/kiali-rhel8, openshift-service-mesh/pilot-rhel8, openshift-service-mesh/proxyv2-rhel9, openshift-service-mesh/istio-cni-rhel8, openshift-service-mesh/istio-rhel8-operator, openshift-service-mesh/istio-must-gather-rhel9 Red Hat OpenShift Service Mesh 3 openshift-service-mesh/kiali-rhel9, openshift-service-mesh/istio-cni-rhel9, openshift-service-mesh/istio-pilot-rhel9, openshift-service-mesh/istio-proxyv2-rhel9, openshift-service-mesh/istio-rhel9-operator, openshift-service-mesh/kiali-rhel9-operator, +2 more Red Hat Pen Drive Powered by Red Hat Lightspeed pen-drive/pen-drive-scanner-rhel9 Red Hat Power monitoring for Red Hat OpenShift openshift-power-monitoring/kepler-rhel9, openshift-power-monitoring/power-monitoring-rhel9-operator, openshift-power-monitoring/power-monitoring-operator-bundle Red Hat 3scale API Management Platform 2 3scale-amp2/3scale-rhel7-operator, 3scale-amp2/3scale-rhel9-operator, 3scale-amp2/3scale-operator-bundle, 3scale-amp2/apicast-rhel7-operator, 3scale-amp2/apicast-rhel9-operator, 3scale-amp2/3scale-apicast-operator-bundle Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/subctl-rhel9, rhacm2/thanos-rhel9, rhacm2/acm-cli-rhel9, rhacm2/volsync-rhel9, rhacm2/prometheus-rhel9, rhacm2/acm-grafana-rhel9, +40 more
    affected: workaround, no fix available “Fix deferred”

37 more affected, 9 more fixed, 25 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
yes
Technical impact
total
Assessed
5 mo ago

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
GitHub 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

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/agent

Classification

Weakness

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.