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Fencer Intel
medium 6.1

CVE-2026-66010 json

DOMPurify before 3.4.12 Hook Bypass via CUSTOM_ELEMENT_HANDLING

published 4mo ago modified 18d ago also EUVD-2026-48582 , GHSA-c2j3-45gr-mqc4

cvss
6.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

DOMPurify before 3.4.12 fails to execute afterSanitizeElements hook for custom elements allowed via CUSTOM_ELEMENT_HANDLING.tagNameCheck, allowing attributes to bypass application security policies. Attackers can preserve sensitive attributes on custom elements that later re-inject them into innerHTML sinks, creating second-order XSS gadgets.

Patch / fix

  • npm dompurify 3.4.12
  • cure53 DOMPurify 3.4.12
  • node-dompurify Debian 14 3.4.12+dfsg-1

debian advisories DEBIAN-CVE-2026-66010

Is CVE-2026-66010 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2026-66010 updated cvss 6.1

dompurify: DOMPurify: Cross-Site Scripting (XSS) via custom element attribute bypass

  • Red Hat Cryostat 4 dompurify, grafana-infinity-datasource-npm, cryostat-openshift-console-plugin-npm Red Hat Migration Toolkit for Virtualization migration-toolkit-virtualization/mtv-console-plugin-rhel9 Red Hat Multicluster Engine for Kubernetes multicluster-engine/console-mce-rhel9 Red Hat Node HealthCheck Operator workload-availability/node-healthcheck-rhel9-operator, workload-availability/node-healthcheck-operator-bundle, workload-availability/node-healthcheck-must-gather-rhel9 Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-console-plugin-rhel9, openshift-lightspeed/lightspeed-agentic-console-rhel9, openshift-lightspeed/lightspeed-console-plugin-419-rhel9, openshift-lightspeed/lightspeed-console-plugin-pf5-rhel9 Red Hat OpenShift Service Mesh 3 openshift-service-mesh/kiali-rhel9, openshift-service-mesh/kiali-ossmc-rhel9
    +25 more products
    Red Hat 3scale API Management Platform 2 3scale-amp21/system, 3scale-amp22/system, 3scale-amp2/system-rhel7, 3scale-amp2/system-rhel8, 3scale-amp2/system-rhel9 Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/console-rhel9 Red Hat Advanced Cluster Security 4 advanced-cluster-security/rhacs-main-rhel8, advanced-cluster-security/rhacs-main-rhel9 Red Hat AMQ Broker 7 dompurify Red Hat Ansible Automation Platform 2 automation-gateway, automation-controller, automation-platform-ui, automation-eda-controller, ansible-automation-platform-26/gateway-rhel9, ansible-automation-platform-27/gateway-rhel9 Red Hat build of Apache Camel - HawtIO 4 dompurify Red Hat build of Apache Camel for Spring Boot 4 dompurify Red Hat build of Apicurio Registry 3 apicurio/apicurio-registry-ui-rhel8, apicurio/apicurio-registry-ui-rhel9 Red Hat Build of Podman Desktop rh-podman-desktop.git Red Hat Ceph Storage 9 rhceph/alloy-rhel10 Red Hat Data Grid 8 dompurify Red Hat Developer Hub 1 rhdh/rhdh-hub-rhel9 Red Hat Enterprise Linux 8 grafana, grafana-loki, grafana-mssql, grafana-mysql, grafana-selinux, grafana-graphite, +8 more Red Hat Enterprise Linux 9 grafana, grafana-selinux Red Hat Enterprise Linux 10 ceph, grafana, grafana-pcp, cockpit-image-builder Red Hat OpenShift AI (RHOAI) rhoai/odh-dashboard-rhel9, rhoai/odh-mod-arch-maas-rhel9, rhoai/odh-mod-arch-automl-rhel9, rhoai/odh-mod-arch-gen-ai-rhel9, rhoai/odh-mod-arch-mlflow-rhel9, rhoai/odh-mod-arch-autorag-rhel9, +3 more Red Hat OpenShift Container Platform 4 openshift4/ose-console, openshift4/ose-console-rhel9, openshift4/ose-monitoring-plugin-rhel8, openshift4/ose-monitoring-plugin-rhel9, openshift4/ose-agent-installer-ui-rhel9 Red Hat OpenShift Container Platform 5 openshift5/ose-console-rhel9, openshift5/ose-monitoring-plugin-rhel9, openshift5/ose-agent-installer-ui-rhel9 Red Hat Openshift Data Foundation 4 odf4/odf-console-rhel9, odf4/ocs-client-console-rhel9, odf4/odf-multicluster-console-rhel9 Red Hat OpenShift Dev Spaces devspaces/code-rhel9, devspaces/openvsx-rhel9 Red Hat OpenShift GitOps openshift-gitops-1/argocd-rhel8, openshift-gitops-1/argocd-rhel9 Red Hat OpenShift Virtualization 4 container-native-virtualization/kubevirt-console-plugin, container-native-virtualization/kubevirt-console-plugin-rhel9 Red Hat Self-service automation portal 2 ansible-automation-platform/automation-portal Red Hat streams for Apache Kafka 2 dompurify Red Hat streams for Apache Kafka 3 dompurify
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images ruff 0.15.11-1.hum1
    not affected: vulnerable code not present

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
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
3mo ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 5.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
CNA 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CNA 4.0 5.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
npm dompurify
<3.4.12
3.4.12

Affected products

  • cure53 DOMPurify

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation
  • CWE-184 Incomplete List of Disallowed Inputs
  • CWE-693 Protection Mechanism Failure

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.

The maintainers of cure53/DOMPurify published their own advisory on GitHub. Reviewed sources take precedence over it.