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Fencer Intel
high 7.5

CVE-2026-78660 json

HTTP/2 transport accepts malformed framing-related headers in net/http

published last mo. modified 26d ago also BIT-golang-2026-78660 , EUVD-2026-95425 , GO-2026-6610

cvss
7.5
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 46%
public exploits
0
none known

Summary

Historically, we have been rather lax about malformed framing-related headers in our HTTP/2 implementation, as they cannot interfere with HTTP/2 framing. However, this makes it possible for our HTTP/2 implementation to forward responses containing such headers to an HTTP/1 client when acting as a reverse proxy. If the HTTP/1 client also does not behave strictly enough, this can result in response smuggling.

Patch / fix

  • bitnami golang 1.26.9, 1.27.2
  • go stdlib 1.26.9, 1.27.2
  • go golang.org/x/net 0.60.0
  • Go standard library net/http 1.26.9
  • Go standard library net/http/internal/http2 1.27.2
  • golang.org/x/net golang.org/x/net/http2 0.60.0
  • golang-1.26 Debian 14 1.26.9-1
  • golang-1.27 Debian 14 1.27.2-1
  • golang-golang-x-net Debian 14 1:0.60.0-1

debian advisories DEBIAN-CVE-2026-78660

  • golang-1.22 Ubuntu 22.04 LTS 1.22.2-2~22.04.4
  • golang-1.22 Ubuntu 24.04 LTS 1.22.2-2ubuntu0.5

ubuntu advisories UBUNTU-CVE-2026-78660

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

  • kubevirt SLE Module for Containers 15 SP7 1.7.4-150700.3.42.1
  • google-cloud-sap-agent SLES for SAP applications 16.0, SLES 16.0 3.15-160000.5.1
  • google-guest-agent Linux Micro 6.0 20261022.00-159998.1.1
  • google-guest-agent Linux Micro 6.1 20261022.00-slfo.1.1_1.1
  • go1.26-openssl SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +5 more 1.26.10-150000.1.21.2
  • go1.26-openssl SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Development Tools 15 SP7 1.26.10-150600.13.18.1
  • go1.26 SLES for SAP applications 16.0, SLES 16.0 1.26.9-160000.1.1
  • go1.27 SLES for SAP applications 16.0, SLES 16.0 1.27.2-160000.1.1

suse advisories SUSE-SU-2026:5167-1SUSE-SU-2026:24604-1SUSE-SU-2026:24475-1SUSE-SU-2026:24555-1SUSE-SU-2026:4867-1SUSE-SU-2026:4866-1

  • alloy openSUSE Tumbleweed 1.21.3-1.1
  • google-cloud-sap-agent openSUSE Leap 16.0 3.15-160000.5.1
  • kubevirt1.9 openSUSE Leap 16.0 1.9.1-160000.1.1
  • fleet-cli openSUSE Tumbleweed 0.16.3-1.1
  • helm openSUSE Tumbleweed 4.3.1-3.1
  • distribution openSUSE Tumbleweed 3.1.2-3.1
  • prometheus-ha_cluster_exporter openSUSE Tumbleweed 1.4.3-1.1
  • timoni openSUSE Tumbleweed 0.36.0-1.1

opensuse advisories openSUSE-SU-2026:12446-1openSUSE-SU-2026:22236-1openSUSE-SU-2026:22180-1openSUSE-SU-2026:12320-1openSUSE-SU-2026:12326-1openSUSE-SU-2026:12283-1

  • golang AlmaLinux 10 1.26.10-1.el10_2.alma.1
  • go-toolset AlmaLinux 10 1.26.10-1.el10_2.alma.1
  • golang-bin AlmaLinux 10 1.26.10-1.el10_2.alma.1
  • golang-src AlmaLinux 10 1.26.10-1.el10_2.alma.1
  • golang-misc AlmaLinux 10 1.26.10-1.el10_2.alma.1
  • golang-race AlmaLinux 10 1.26.10-1.el10_2.alma.1
  • golang-tests AlmaLinux 10 1.26.10-1.el10_2.alma.1
  • golang AlmaLinux 9 1.26.10-1.el9_8

almalinux advisories ALSA-2026:86093ALSA-2026:86196ALSA-2026:86203

  • go Alpine 3.24 1.26.9-r0

alpine advisories ALPINE-CVE-2026-78660

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • application-gateway-kubernetes-ingress Azure Linux 3.0 1.7.7-7
  • azcopy Azure Linux 3.0 10.25.1-10
  • azurelinux-image-tools Azure Linux 3.0 1.7.0-2
  • cert-manager Azure Linux 3.0 1.12.15-15
  • cf-cli Azure Linux 3.0 8.7.11-10
  • cloud-provider-kubevirt Azure Linux 3.0 0.5.1-10
  • containerd2 Azure Linux 3.0 2.3.7-1
  • containerized-data-importer Azure Linux 3.0 1.62.0-9

azure linux advisories AZL-107141AZL-107156AZL-107177AZL-107186AZL-107204AZL-107225

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

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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-2026-78660 updated cvss 7.5

net/http: golang: golang.org/x/net/http2: net/http: HTTP response smuggling via malformed HTTP/2 framing headers

  • Red Hat Assisted Installer for Red Hat OpenShift Container Platform 2 rhai/assisted-installer-rhel9
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat AWS Load Balancer Operator albo/aws-load-balancer-rhel8-operator, albo/aws-load-balancer-controller-rhel8 Red Hat Builds for Red Hat OpenShift openshift-builds/openshift-builds-waiters-rhel9, openshift-builds/openshift-builds-waiters-rhel10 Red Hat cert-manager Operator for Red Hat OpenShift cert-manager/jetstack-cert-manager-rhel9, cert-manager/cert-manager-istio-csr-rhel9, cert-manager/cert-manager-trust-manager-rhel9, cert-manager/jetstack-cert-manager-acmesolver-rhel9 Red Hat Compliance Operator compliance/openshift-compliance-operator-bundle Red Hat Confidential Compute Attestation build-of-trustee/trustee-rhel9-operator Red Hat Cost Management Metrics Operator costmanagement/costmanagement-metrics-rhel9-operator
    +4 more products
    Red Hat Cost Management On Premise costmanagement/costmanagement-ros-ocp-backend-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-admission-webhooks-rhel9, custom-metrics-autoscaler/custom-metrics-autoscaler-http-add-on-scaler-rhel9, custom-metrics-autoscaler/custom-metrics-autoscaler-http-add-on-operator-rhel9, custom-metrics-autoscaler/custom-metrics-autoscaler-http-add-on-interceptor-rhel9 Red Hat Deployment Validation Operator dvo/deployment-validation-rhel8-operator Red Hat DPU kit for NVIDIA dpu-kit-for-nvidia/dpf-hcp-provisioner-rhel10-operator
    affected: workaround, no fix available
  • Red Hat Exploit Intelligence exploit-intelligence/exploit-intelligence-operator-controller-rhel9
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat External Secrets Operator for Red Hat OpenShift external-secrets-operator/external-secrets-rhel9
    affected: workaround, no fix available
  • Red Hat Fence Agents Remediation Operator workload-availability/fence-agents-remediation-rhel8-operator
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat File Integrity Operator compliance/openshift-file-integrity-rhel8-operator Red Hat Gatekeeper 3 gatekeeper/gatekeeper-rhel9-operator Red Hat Helm CLI for Red Hat OpenShift helm-cli/helm-cli-rhel9
    affected: workaround, no fix available
  • Red Hat Logical Volume Manager Storage lvms4/topolvm-rhel8, lvms4/topolvm-rhel9 Red Hat Machine Deletion Remediation Operator workload-availability/machine-deletion-remediation-rhel8-operator Red Hat Migration Toolkit for Containers rhmtc/openshift-migration-registry-rhel8
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Multiarch Tuning Operator multiarch-tuning/multiarch-tuning-rhel9-operator Red Hat Multicluster Engine for Kubernetes multicluster-engine/maestro-rhel9 Red Hat Multicluster Global Hub multicluster-globalhub/multicluster-globalhub-agent-rhel9 Red Hat Network Observability Operator network-observability/network-observability-cli-rhel9
    affected: workaround, no fix available
show 8 more
  • Red Hat Node HealthCheck Operator workload-availability/node-healthcheck-rhel8-operator Red Hat Node Maintenance Operator workload-availability/node-maintenance-operator-bundle
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Nvidia GPU Driver for RHEL on Openshift nvidia/doca-driver-rhel9 Red Hat OpenShift API for Data Protection oadp/oadp-velero-rhel9
    affected: workaround, no fix available
  • Red Hat OpenShift Developer Tools and Services helm 3.22.0-90.el9
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat OpenShift Lightspeed openshift-lightspeed/otelcol-lightspeed-rhel9 Red Hat OpenShift Pipelines openshift-pipelines-client 1.15.3-11580.el8, openshift-pipelines/pipelines-scheduler-rhel9
    affected: workaround, no fix available
  • Red Hat OpenShift Serverless kn-workflow-plugin 1.38.1-1.el9, openshift-serverless-clients 1.17.0-4.el9, openshift-serverless-1/logic-rhel9-operator, openshift-serverless-1/kn-plugin-event-sender-rhel9 Red Hat OpenShift Service Mesh 3 istio-proxy-selinux, istio-proxy 1.30.5-1.el9, openshift-golang-builder-container
    affected: workaround, no fix available “Fix deferred”
  • Red Hat OpenShift Source-to-Image (S2I) source-to-image/source-to-image-rhel8 Red Hat 3scale API Management Platform 2 3scale-amp2/3scale-rhel9-operator, 3scale-amp2/apicast-rhel9-operator Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/subctl-rhel9 Red Hat Advanced Cluster Security 4 advanced-cluster-security/rhacs-main-rhel8, advanced-cluster-security/rhacs-main-rhel9
    affected: workaround, no fix available
  • Red Hat Ansible Automation Platform 2 receptor 1.6.9-1.el9ap, automation-gateway-proxy 2.6.17-3.el9ap, ansible-automation-platform-26/receptor-rhel9, ansible-automation-platform-27/receptor-rhel9, ansible-on-clouds/aoc-azure-aap-installer-rhel9, automation-gateway-proxy-openssl30 2.6.6-2.el9ap, +1 more
    affected: workaround, no fix available, no fix planned “Out of support scope”
  • Red Hat Ceph Storage 5 rhceph/snmp-notifier-rhel8 Red Hat Ceph Storage 6 rhceph/snmp-notifier-rhel9
    affected: workaround, no fix available “Fix deferred”

42 more affected, 49 more under investigation, 13 more fixed, 9 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
last mo.

Exploit prediction

0.54% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-11).

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:N/I:H/A:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
bitnami golang
<1.26.9
>=1.27.0-0, <1.27.2
1.26.9
1.27.2
go stdlib
<1.26.9
>=1.27.0-0, <1.27.2
1.26.9
1.27.2
go golang.org/x/net
<0.60.0
0.60.0

Affected products

  • Go standard library net/http
  • Go standard library net/http/internal/http2
  • golang.org/x/net golang.org/x/net/http2

Classification

Weakness
  • CWE-444 Inconsistent Interpretation of HTTP Requests

References

Sources

Fencer Intel 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.