CVE-2026-65912: Dompurify DOMPurify ADD_ATTR Predicate Skips URI Vulnerability

MODERATE
Advisory Identifier: GHSA-cjmm-f4jc-qw8r
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CWE-183
Published
Advisory Summary

CVE-2026-65912 is a MODERATE dompurify add_attr predicate skips uri vulnerability (CWE-183: Permissive List of Allowed Inputs) affecting Dompurify libraries in the npm ecosystem. The issue involves dompurify add_attr predicate skips uri validation. Remediation is available by upgrading affected packages to version 3.3.2.

CVE-2026-65912 at a Glance

CVE Identifier CVE-2026-65912
GHSA Identifier GHSA-cjmm-f4jc-qw8r
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-183: Permissive List of Allowed Inputs
Affected Product Dompurify
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-65912

To remediate this vulnerability, upgrade all affected Dompurify dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

dompurify fixed: 3.3.2 
npm install dompurify@3.3.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls dompurify

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-65912, inspect your project dependencies using npm:

npm ls dompurify

Analyze the terminal output to locate any version of Dompurify in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.3.2), your application is affected.

Note: The npm ls dompurify command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-183: Permissive List of Allowed Inputs, where the product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are explicitly allowed by policy because the inputs are assumed to be safe, but the list is too permissive - that is, it allows an input that is unsafe, leading to resultant weaknesses. In Dompurify, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Summary DOMPurify allows `ADD_ATTR` to be provided as a predicate function via `EXTRA_ELEMENT_HANDLING.attributeCheck`. When the predicate returns `true`, `_isValidAttribute` short-circuits the attribute check before URI-safe validation runs. An attacker who supplies a predicate that accepts specific attribute/tag combinations can then sanitize input such as `<a href="javascript:alert(document.domain)">` and have the `javascript:` URL survive, because URI validation is skipped for that attribute while other checks still pass. The provided PoC accepts `href` for anchors and then triggers a click inside an iframe, showing that the sanitized payload executes despite the protocol bypass. ## Impact Predicate-based allowlisting bypasses DOMPurify's URI validation, allowing unsafe protocols such as `javascript:` to reach the DOM and execute whenever the link is activated, resulting in DOM-based XSS. ## Credits Identified by Cantina’s Apex (https://www.cantina.security).

CVE-2026-65912 Affected Dompurify Versions

1 component(s)
Fixed Versions:
3.3.2
Product / Package Ecosystem Affected Versions Fixed Version
dompurify
npm/dompurify
npm
< 3.3.2
3.3.2

References

GitHub Advisory / Wiki ADVISORY
https://github.com/cure53/DOMPurify/security/advisories/GHSA-cjmm-f4jc-qw8r
Dompurify Source Repository REPOSITORY
https://github.com/cure53/DOMPurify
Dompurify Release RELEASE
https://github.com/cure53/DOMPurify/releases/tag/3.3.2

Frequently Asked Questions

What is CVE-2026-65912?
CVE-2026-65912 is a security vulnerability in Dompurify involving DOMPurify ADD_ATTR predicate skips URI validation under CWE-183: Permissive List of Allowed Inputs.
Which Dompurify versions are affected?
Affected versions include releases prior to 3.3.2 across affected packages: dompurify.
What version fixes CVE-2026-65912?
Upgrading to 3.3.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is dompurify affected?
Yes, dompurify is affected in releases prior to 3.3.2. Upgrade your dependency to 3.3.2 or later.
What CWE is associated with CVE-2026-65912?
CVE-2026-65912 is classified under CWE-183: Permissive List of Allowed Inputs (The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are explicitly allowed by policy because the inputs are assumed to be safe, but the list is too permissive - that is, it allows an input that is unsafe, leading to resultant weaknesses.).
How can I check npm dependencies for CVE-2026-65912?
Run the dependency tree command: 'npm ls dompurify'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-cjmm-f4jc-qw8r",
  "modified" : "2026-07-23T14:04:34Z",
  "published" : "2026-04-03T03:46:07Z",
  "aliases" : [ "CVE-2026-65912" ],
  "summary" : "DOMPurify ADD_ATTR predicate skips URI validation",
  "details" : "## Summary\nDOMPurify allows `ADD_ATTR` to be provided as a predicate function via `EXTRA_ELEMENT_HANDLING.attributeCheck`. When the predicate returns `true`, `_isValidAttribute` short-circuits the attribute check before URI-safe validation runs. An attacker who supplies a predicate that accepts specific attribute/tag combinations can then sanitize input such as `<a href=\"javascript:alert(document.domain)\">` and have the `javascript:` URL survive, because URI validation is skipped for that attribute while other checks still pass. The provided PoC accepts `href` for anchors and then triggers a click inside an iframe, showing that the sanitized payload executes despite the protocol bypass.\n\n## Impact\nPredicate-based allowlisting bypasses DOMPurify's URI validation, allowing unsafe protocols such as `javascript:` to reach the DOM and execute whenever the link is activated, resulting in DOM-based XSS.\n\n## Credits\nIdentified by Cantina’s Apex (https://www.cantina.security).",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "dompurify"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.3.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.3.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/cure53/DOMPurify/security/advisories/GHSA-cjmm-f4jc-qw8r"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/cure53/DOMPurify"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cure53/DOMPurify/releases/tag/3.3.2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-183" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-03T03:46:07Z",
    "nvd_published_at" : null
  }
}