DOMPurify before 3.4.12 Hook Bypass via CUSTOM_ELEMENT_HANDLING
Priority MEDIUM 56CWE-79Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Active
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Cross-site scripting, Security bypass
- Confidentiality · integrity · availability
- None · None · None
- Fix status
- Partial Red Hat: 31 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-79 and CWE-693.
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00215 12th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial DOMPurify (cure53): 3.4.12dompurify (npm): 3.4.12Red Hat: 31 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| cure53 | DOMPurify | before 3.4.12 | 3.4.12 | Patch available | CNA |
| — | dompurify (npm) | before 3.4.12 | 3.4.12 | Patch available | GHSA-c2j3-45gr-mqc4 |
- DOMPurify Vendorcure53 Affected before 3.4.12 Fixed in 3.4.12 Patch available CNA
- dompurify (npm) Vendor— Affected before 3.4.12 Fixed in 3.4.12 Patch available GHSA-c2j3-45gr-mqc4
Remediation
- Fix · CNA DOMPurify (cure53) Fixed in 3.4.12
- Fix · GHSA-c2j3-45gr-mqc4 dompurify (npm) Fixed in 3.4.12 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Cryostat 4 | Affected | No fix yet: Fix deferred |
| Migration Toolkit for Virtualization | Affected | No fix yet: Fix deferred |
| Multicluster Engine for Kubernetes | Affected | No fix yet: Fix deferred |
| Node HealthCheck Operator | Affected | No fix yet: Fix deferred |
| OpenShift Lightspeed | Affected | No fix yet: Fix deferred |
| OpenShift Service Mesh 3 | Affected | No fix yet: Fix deferred |
| Red Hat 3scale API Management Platform 2 | Affected | No fix yet: Fix deferred |
| Red Hat AMQ Broker 7 | Affected | No fix yet: Fix deferred |
| Red Hat Advanced Cluster Management for Kubernetes 2 | Affected | No fix yet: Fix deferred |
| Red Hat Advanced Cluster Security 4 | Affected | No fix yet: Fix deferred |
| Red Hat Ansible Automation Platform 2 | Affected | No fix yet: Fix deferred |
| Red Hat Build of Podman Desktop | Affected | No fix yet: Fix deferred |
| Red Hat Ceph Storage 9 | Affected | No fix yet: Fix deferred |
| Red Hat Data Grid 8 | Affected | No fix yet: Fix deferred |
| Red Hat Developer Hub 1 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift AI (RHOAI) | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Dev Spaces | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift GitOps | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Virtualization 4 | Affected | No fix yet: Fix deferred |
| Red Hat Openshift Data Foundation 4 | Affected | No fix yet: Fix deferred |
| Red Hat build of Apache Camel - HawtIO 4 | Affected | No fix yet: Fix deferred |
| Red Hat build of Apache Camel for Spring Boot 4 | Affected | No fix yet: Fix deferred |
| Red Hat build of Apicurio Registry 3 | Affected | No fix yet: Fix deferred |
| Self-service automation portal 2 | Affected | No fix yet: Fix deferred |
| streams for Apache Kafka 2 | Affected | No fix yet: Fix deferred |
| streams for Apache Kafka 3 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Hardened Images
Timeline
- 2026-10-02 Threatist record created from CVE-2026-66010
- 2026-10-03 Alias added: GHSA-c2j3-45gr-mqc4
- 2026-10-27 Affected versions changed · Red Hat
- 2026-11-01 Affected versions changed · Red Hat
References
More cure53 Dompurify vulnerabilities
- TI-2026-34986 DOMPurify XSS via `selectedcontent` re-clone CVSS 3.1HIGH 8.2
- TI-2026-36811 DOMPurify IN_PLACE Sanitization Bypass via Attached Shadow Root Inside <template>.content CVSS 4.0MEDIUM 6.3
- TI-2026-36614 DOMPurify: IN_PLACE mode preserves attributes of a clobbered root element, allowing XSS via attacker-controlled root DOM CVSS 3.1MEDIUM 6.1
- TI-2026-36613 DOMPurify: Cross-realm IN_PLACE sanitization leaves executable markup intact via realm-bound `instanceof` checks CVSS 3.1MEDIUM 6.1
- TI-2026-29849 DOMPurify: FORBID_TAGS bypassed by function-based ADD_TAGS predicate (asymmetry with FORBID_ATTR fix) CVSS 4.0MEDIUM 6.0
- TI-2025-19705 Cross-site scripting in cure53 DOMPurify CVSS 3.1MEDIUM 6.1
Sources
- CVE-2026-66010 · CVE Program
- CVE-2026-66010 · NVD
- FIRST EPSS
- GHSA-c2j3-45gr-mqc4 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-66010 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences