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Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-44990

CRITICAL · 9.3 CVSS v3.1 Published 2026-06-12
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. Under the default configuration, versions of `sanitize-html` prior to 2.17.4 can turn attacker-controlled content inside a disallowed `xmp` element into live HTML or JavaScript. This is a sanitizer bypass in the default `disallowedTagsMode: 'discard'` path and can lead to stored XSS in applications that render sanitized output back to users. Version 2.17.4 patches the issue.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The sanitize-html library versions prior to 2.17.4 contain a sanitizer bypass where attacker-controlled content inside a disallowed `xmp` element can be transformed into live HTML or JavaScript in the default `disallowedTagsMode: 'discard'` configuration, enabling stored XSS in applications that render sanitized content.

MitigationUpgrade sanitize-html to version 2.17.4 or later to patch the XSS bypass in the `xmp` element handling.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check sanitize-html version
    Run `npm list sanitize-html` or inspect the version field in node_modules/sanitize-html/package.json
    Affected if The installed version is earlier than 2.17.4 (e.g., 2.17.3, 2.16.0, etc.)
  2. Identify sanitize-html usage in your codebase
    Search for `require('sanitize-html')` or `import ... from 'sanitize-html'` to locate where sanitization is performed
    Affected if Your application uses sanitize-html to clean user-supplied HTML content
  3. Verify sanitize-html configuration
    Inspect the options object passed to sanitize-html() and look for the disallowedTagsMode setting
    Affected if disallowedTagsMode is set to 'discard' (the default) or is not explicitly set to 'escape' or 'recursiveEscape'
  4. Check if xmp tags can appear in user content
    Review your data flow to determine whether users can submit content containing <xmp> tags that gets processed by sanitize-html
    Affected if User-provided HTML containing <xmp> elements passes through the sanitizer before rendering

You are affected if sanitize-html version is below 2.17.4 AND your application sanitizes user content using the default configuration, and <xmp> tags from users can reach the sanitizer.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade sanitize-html to version 2.17.4 or later to patch the XSS bypass in the `xmp` element handling.

Recommended fix High confidence

sanitize-html version 2.17.4

  1. Update the sanitize-html package to version 2.17.4 or later using your package manager (e.g., npm install [email protected] or npm update sanitize-html)
  2. Verify that the xmp element is now properly handled in the disallowed tags path
  3. Test that sanitized HTML output no longer executes malicious scripts injected within xmp tags
  4. Redeploy the updated application to production environments

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-44990 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data