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Fencer Vulns
high 7.5

CVE-2026-78659 json

HTTP/2 server memory exhaustion due to Trailer headers in net/http

published 2026-10-08 31 d ago modified 2026-10-16 23 d ago also BIT-golang-2026-78659 , EUVD-2026-95419 , GO-2026-6603

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 58%
public exploits
0
none known

Summary

When "Trailer" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler. Because Request.Trailer is a map, each entry incurs memory overhead. For HTTP/2 servers, a malicious client can exploit this by sending a "Trailer" header that declares a large number of fields, causing the server to allocate a disproportionate amount of memory while bypassing Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits. This exploit is not applicable for HTTP/1 servers, which do not support multiplexing a large number of requests over one TCP connection, and whose Server.MaxHeaderBytes are calculated differently.

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-2026-78659

  • 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-2026-78659

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

  • 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
  • go1.26 SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 1.26.9-150000.1.33.1

suse advisories SUSE-SU-2026:24604-1SUSE-SU-2026:24475-1SUSE-SU-2026:24555-1SUSE-SU-2026:4867-1SUSE-SU-2026:4866-1SUSE-SU-2026:24239-1

  • alloy openSUSE Tumbleweed 1.21.3-1.1
  • tempo-cli openSUSE Tumbleweed 3.1.1-1.1
  • 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
  • google-guest-agent openSUSE Tumbleweed 20261022.00-1.1
  • google-osconfig-agent openSUSE Tumbleweed 20261022.00-1.1

opensuse advisories openSUSE-SU-2026:12446-1openSUSE-SU-2026:12351-1openSUSE-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
  • docker Alpine 3.24 29.9.0-r0

alpine advisories ALPINE-CVE-2026-78659

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
  • azurelinux-image-tools Azure Linux 3.0 1.7.0-2
  • cert-manager Azure Linux 3.0 1.12.15-15
  • 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
  • coredns Azure Linux 3.0 1.11.4-23
  • docker-buildx Azure Linux 3.0 0.14.0-19

azure linux advisories AZL-107135AZL-107165AZL-107180AZL-107216AZL-107240AZL-107255

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-2026-78659 updated cvss 7.5

net/http: golang.org/x/net/http2: golang: net/http: Denial of Service via HTTP/2 trailer header memory exhaustion

  • Red Hat Ansible Automation Orchestrator 2026 ansible-automation-platform/automation-orchestrator-rhel9-operator, ansible-automation-platform/automation-orchestrator-operator-bundle Red Hat Assisted Installer for Red Hat OpenShift Container Platform 2 rhai/assisted-installer-rhel9, rhai/assisted-installer-agent-rhel9, rhai/assisted-installer-controller-rhel9, assisted/agent-preinstall-image-builder-rhel9 Red Hat AWS Load Balancer Operator albo/aws-load-balancer-rhel8-operator, albo/aws-load-balancer-controller-rhel8 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, agent-sandbox/agent-sandbox-rhel9-operator, openshift-sandboxed-containers/osc-monitor-rhel9, openshift-sandboxed-containers/osc-rhel9-operator, openshift-sandboxed-containers/osc-podvm-payload-rhel9, openshift-sandboxed-containers/osc-cloud-api-adaptor-rhel9, +1 more
    +25 more products
    Red Hat Cost Management Metrics Operator costmanagement/costmanagement-metrics-rhel9-operator Red Hat Cost Management On Premise costmanagement/costmanagement-ingress-rhel9, costmanagement/costmanagement-ros-ocp-backend-rhel9 Red Hat Cryostat 4 cryostat/cryostat-storage-rhel9, cryostat/cryostat-rhel9-operator, 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, custom-metrics-autoscaler/custom-metrics-autoscaler-http-add-on-scaler-rhel9, custom-metrics-autoscaler/custom-metrics-autoscaler-http-add-on-operator-rhel9, +1 more 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 Red Hat Exploit Intelligence exploit-intelligence/exploit-intelligence-operator-controller-rhel9 Red Hat External Secrets Operator for Red Hat OpenShift external-secrets-operator/external-secrets-rhel9 Red Hat Fence Agents Remediation Operator workload-availability/fence-agents-remediation-rhel8-operator, workload-availability/fence-agents-remediation-operator-bundle Red Hat File Integrity Operator compliance/openshift-file-integrity-rhel8-operator, compliance/openshift-file-integrity-operator-bundle Red Hat Gatekeeper 3 gatekeeper/gatekeeper-rhel9-operator Red Hat Helm CLI for Red Hat OpenShift helm-cli/helm-cli-rhel9 Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/eventrouter-rhel9, openshift-logging/logging-loki-rhel9, openshift-logging/loki-rhel9-operator, openshift-logging/opa-openshift-rhel9, openshift-logging/lokistack-gateway-rhel9, openshift-logging/cluster-logging-rhel9-operator, +1 more Red Hat Logical Volume Manager Storage lvms4/topolvm-rhel8, lvms4/topolvm-rhel9, lvms4/lvms-rhel8-operator, lvms4/lvms-rhel9-operator, lvms4/lvms-operator-bundle, lvms4/lvms-must-gather-rhel8, +1 more Red Hat Machine Deletion Remediation Operator workload-availability/machine-deletion-remediation-rhel8-operator, workload-availability/machine-deletion-remediation-operator-bundle Red Hat Migration Toolkit for Applications 8 mta/mta-cli-rhel9, mta/mta-hub-rhel9, mta/mta-analyzer-addon-rhel9, mta/mta-platform-addon-rhel9, mta/mta-discovery-addon-rhel9, mta/mta-go-external-provider-rhel9, +3 more Red Hat Migration Toolkit for Containers rhmtc/openshift-migration-registry-rhel8, rhmtc/openshift-migration-controller-rhel8, rhmtc/openshift-migration-rsync-transfer-rhel8, rhmtc/openshift-migration-velero-plugin-for-mtc-rhel8 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/maestro-rhel9, multicluster-engine/discovery-rhel9, multicluster-engine/assisted-installer-rhel8, multicluster-engine/assisted-installer-rhel9, multicluster-engine/assisted-service-8-rhel8, multicluster-engine/assisted-service-9-rhel9, +22 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-cli-rhel9, network-observability/network-observability-rhel9-operator, network-observability/network-observability-ebpf-agent-rhel9, network-observability/network-observability-flowlogs-pipeline-rhel9 Red Hat Node HealthCheck Operator workload-availability/node-healthcheck-rhel8-operator, workload-availability/node-healthcheck-operator-bundle Red Hat Node Maintenance Operator workload-availability/node-maintenance-operator-bundle, container-native-virtualization/node-maintenance-operator Red Hat Nvidia GPU Driver for RHEL on Openshift nvidia/doca-driver-rhel9 Red Hat OpenShift API for Data Protection oadp/oadp-velero-rhel9, oadp/oadp-rhel9-operator, oadp/oadp-non-admin-rhel9, oadp/oadp-mustgather-rhel9, oadp/oadp-cli-binaries-rhel9, oadp/oadp-velero-plugin-rhel9, +8 more
    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, openshift-lightspeed/lightspeed-rhel9-operator, openshift-lightspeed/openshift-mcp-server-rhel9, openshift-lightspeed/lightspeed-agentic-rhel9-operator, openshift-lightspeed/lightspeed-agentic-alerts-adapter-rhel9 Red Hat OpenShift Pipelines openshift-pipelines-client 1.15.3-11580.el8 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, openshift-serverless-1/kn-plugin-func-func-util-rhel9, openshift-serverless-1/kn-backstage-plugins-eventmesh-rhel9 Red Hat OpenShift Service Mesh 3 istio-proxy-selinux, istio-proxy 1.30.5-1.el9, openshift-service-mesh/kiali-rhel9, openshift-service-mesh/istio-cni-rhel9, openshift-service-mesh/istio-pilot-rhel9, openshift-service-mesh/istio-proxyv2-rhel9, +1 more Red Hat OpenShift Source-to-Image (S2I) source-to-image/source-to-image-rhel8, source-to-image/source-to-image-rhel9 Red Hat 3scale API Management Platform 2 3scale-amp2/3scale-rhel9-operator, 3scale-amp2/3scale-operator-bundle, 3scale-amp2/apicast-rhel9-operator, 3scale-amp2/3scale-apicast-operator-bundle
    +2 more products
    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, +47 more 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
    affected: workaround, no fix available

45 more affected, 13 more fixed, 16 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
30 d ago

Exploit prediction

0.87% chance of exploitation in the next 30 days, higher than 58% 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:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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-405 Asymmetric Resource Consumption (Amplification)

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.