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Fencer Vulns
high 7.5

CVE-2026-56854 json

Source-address critical option not enforced for non-public-key auth callbacks in golang.org/x/crypto/ssh

published 2026-08-28 2 mo ago modified 2026-09-03 2 mo ago also EUVD-2026-67741 , GO-2026-6303

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

The source-address critical option in the Permissions returned by an authentication callback was only enforced for the PublicKeyCallback and VerifiedPublicKeyCallback paths, extending the fix for CVE-2026-46595. Permissions returned by the PasswordCallback, KeyboardInteractiveCallback, NoClientAuthCallback, and GSSAPIWithMICConfig.AllowLogin callbacks were not validated against the client's remote address, so a source-address restriction set by those callbacks was silently ignored. The check is now applied to the Permissions returned by any authentication callback.

Patch / fix

  • go golang.org/x/crypto 0.55.0
  • golang.org/x/crypto golang.org/x/crypto/ssh 0.55.0
  • golang-go.crypto Debian 14 1:0.55.0-1

debian advisories DEBIAN-CVE-2026-56854

  • helm Linux Micro 6.1 4.3.0-slfo.1.1_1.1
  • terraform-provider-aws SLE Module for Public Cloud 15 SP5, SLE Module for Public Cloud 15 SP4 3.11.0-150200.6.29.2
  • terraform-provider-tls SLE Module for Public Cloud 15 SP5, SLE Module for Public Cloud 15 SP4 3.0.0-150200.5.26.2
  • terraform-provider-helm SLE Module for Public Cloud 15 SP5, SLE Module for Public Cloud 15 SP4 2.9.0-150200.6.34.2
  • terraform-provider-null SLE Module for Public Cloud 15 SP5, SLE Module for Public Cloud 15 SP4 3.0.0-150200.6.32.2
  • terraform-provider-local SLE Module for Public Cloud 15 SP5, SLE Module for Public Cloud 15 SP4 2.0.0-150200.6.30.2
  • terraform-provider-google SLE Module for Public Cloud 15 SP5, SLE Module for Public Cloud 15 SP4 3.43.0-150200.6.23.2
  • terraform-provider-random SLE Module for Public Cloud 15 SP5, SLE Module for Public Cloud 15 SP4 3.0.0-150200.6.26.2

suse advisories SUSE-SU-2026:24282-1SUSE-SU-2026:4628-1SUSE-SU-2026:24213-1SUSE-SU-2026:24148-1SUSE-SU-2026:4408-1SUSE-SU-2026:23973-1

  • kubevirt1.8 openSUSE Tumbleweed 1.8.4-7.1
  • zk openSUSE Tumbleweed 0.15.7-1.1
  • cosign openSUSE Leap 16.0 3.1.3-160000.1.1
  • alloy openSUSE Leap 16.0 1.19.2-160000.1.1
  • helm openSUSE Leap 16.0 4.3.0-160000.1.1
  • rclone openSUSE Leap 16.0 1.75.1-bp160.1.1
  • cloudflared openSUSE Leap 16.0 2026.9.1-bp160.1.1
  • apptainer openSUSE Leap 16.0 1.5.3-bp160.4.1

opensuse advisories openSUSE-SU-2026:12241-1openSUSE-SU-2026:12258-1openSUSE-SU-2026:22064-1openSUSE-SU-2026:22032-1openSUSE-SU-2026:21983-1openSUSE-SU-2026:21999-1

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-2026-56854 updated cvss 6.8

golang.org/x/crypto/ssh: golang.org/x/crypto/ssh: Authentication bypass due to unenforced source-address restrictions

  • Red Hat ExternalDNS Operator edo/external-dns-rhel9 Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/cluster-logging-rhel9-operator Red Hat OpenShift Pipelines openshift-pipelines-client, openshift-pipelines/pipelines-cli-tkn-rhel9, openshift-pipelines/pipelines-rhel9-operator, openshift-pipelines/pipelines-resolvers-rhel9, openshift-pipelines/pipelines-controller-rhel9, openshift-pipelines/pipelines-results-api-rhel9, +5 more Red Hat OpenShift Container Platform 4 openshift4/ose-kube-rbac-proxy-rhel9 Red Hat OpenShift Dev Workspaces Operator devworkspace/devworkspace-project-clone-rhel9
    affected: workaround, no fix available
  • Red Hat OpenShift GitOps microshift-gitops, openshift-gitops-1/argocd-rhel8
    affected: workaround, no fix available, no fix planned “Will not fix”
  • Red Hat Trusted Artifact Signer rhtas/ec-rhel9, rhtas/model-transparency-cli-rhel9, rhtas/model-validation-agent-rhel9, rhtas/model-validation-rhel9-operator
    affected: workaround, no fix available
  • Red Hat Assisted Installer for Red Hat OpenShift Container Platform 2 assisted/agent-preinstall-image-builder-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 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/azure-service-operator-rhel9, multicluster-engine/assisted-installer-agent-rhel9, multicluster-engine/cluster-api-provider-azure-rhel9, multicluster-engine/cluster-api-provider-kubevirt-rhel9 Red Hat OpenShift API for Data Protection oadp/oadp-velero-rhel9, oadp/oadp-mustgather-rhel9, oadp/oadp-velero-restic-restore-helper-rhel9 Red Hat OpenShift Serverless openshift-serverless-clients, openshift-serverless-1/kn-plugin-func-func-util-rhel9
    +19 more products
    Red Hat Advanced Cluster Management for Kubernetes 2 flightctl, flightctl-agent, flightctl-selinux, rhacm2/volsync-rhel9, rhacm2/acm-must-gather-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 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 podman, buildah, podman-tests, buildah-tests, podman-docker, podman-remote, +4 more Red Hat Enterprise Linux 9 podman, buildah, podman-tests, buildah-tests, podman-docker, podman-remote, +5 more Red Hat Enterprise Linux 10 podman, buildah, grafana, gvisor-tap-vsock 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, podman, openshift, podman-tests, podman-docker, podman-remote, +90 more Red Hat OpenShift Container Platform 5 cri-o, openshift, openshift5/ose-ptp-rhel9, openshift5/ose-tests-rhel9, openshift5/ose-dpu-cni-rhel9, openshift5/ose-hyperkube-rhel9, +35 more Red Hat OpenShift for Windows Containers openshift4-wincw/windows-machine-config-rhel9-operator, openshift4-wincw/windows-machine-config-operator-bundle Red Hat OpenShift on AWS rosa Red Hat OpenShift Virtualization 4 container-native-virtualization/cluster-network-addons-operator, container-native-virtualization/cluster-network-addons-operator-rhel9 Red Hat OpenStack Platform 16.2 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 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
    under investigation
  • 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
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.20 cert-manager/cert-manager-operator-rhel9 1790272426, cert-manager/cert-manager-operator-rhel9 1790589855, cert-manager/jetstack-cert-manager-rhel9 1790223279, cert-manager/jetstack-cert-manager-rhel9 1790589912, cert-manager/cert-manager-istio-csr-rhel9 1790223719, cert-manager/cert-manager-istio-csr-rhel9 1790589914
    fixed: vendor fix RHSA-2026:72475
  • Red Hat Cryostat 4 on RHEL 9 cryostat/cryostat-storage-rhel9 4.2.0-22
    fixed: vendor fix RHSA-2026:68333
  • Red Hat DevWorkspace Operator 1.0 devworkspace/devworkspace-rhel9-operator 1791368665
    fixed: vendor fix RHSA-2026:85247
show 4 more
  • Red Hat Advanced Cluster Management for Kubernetes 2.13 rhacm2/kube-rbac-proxy-rhel9 1793020035
    fixed: vendor fix RHSA-2026:92307
  • Red Hat OpenShift Builds 1.8.3 openshift-builds/openshift-builds-waiters-rhel9 1789975925, openshift-builds/openshift-builds-webhook-rhel9 1789976300, openshift-builds/openshift-builds-controller-rhel9 1789975753, openshift-builds/openshift-builds-git-cloner-rhel9 1789976227, openshift-builds/openshift-builds-image-bundler-rhel9 1789975447, openshift-builds/openshift-builds-image-processing-rhel9 1789975085
    fixed: fixed in 1.8.2 RHSA-2026:69945
  • Red Hat OpenShift Builds 1.9.2 openshift-builds/openshift-builds-waiters-rhel10 1789974664, openshift-builds/openshift-builds-webhook-rhel10 1789975556, openshift-builds/openshift-builds-controller-rhel10 1789975237, openshift-builds/openshift-builds-git-cloner-rhel10 1789975753, openshift-builds/openshift-builds-image-bundler-rhel10 1789974870, openshift-builds/openshift-builds-image-processing-rhel10 1789975649
    fixed: fixed in 1.9.1 RHSA-2026:69925
  • Red Hat OpenShift Dev Spaces 3.31 devspaces/traefik-rhel9 1792464177
    fixed: vendor fix RHSA-2026:90321

5 more fixed, 20 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
partial
Assessed
2 mo ago

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
go golang.org/x/crypto
<0.55.0
0.55.0

Affected products

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

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.