CVE-2026-26188

Summary
An authenticated, low-privilege user (able to create/edit forms) can inject arbitrary HTML/JS into the Craft Control Panel (CP) builder and integrations views. User-controlled form labels and integration metadata are rendered with dangerouslySetInnerHTML without sanitization, leading to stored XSS that executes when any admin views the builder/integration screens.

Affected Product

• Ecosystem: Packagist (Craft CMS plugin)
• Package: solspace/craft-freeform
• Version: <= 5.14.6 (latest observed). Likely all 5.x until patched.

Details

• Root cause: Multiple user-controlled strings (field labels, section labels, integration icons, short names, WYSIWYG previews) are injected into React components using dangerouslySetInnerHTML without sanitization.
• Evidence: dangerouslySetInnerHTML on user-controlled properties in bundled CP JS at packages/plugin/src/Resources/js/client/client.js.

PoCs

• Label-based XSS:
  1. In Craft CP, create/edit a Freeform field and set its label to <img src=x onerror="alert('xss-label')">.
  2. Open the form builder view containing the field.
  3. Alert executes (stored XSS).
• Integration icon SVG:
  1. Set an integration "icon SVG" to <svg><script>alert('xss-icon')</script></svg>.
  2. Open the integrations CP view.
  3. Script executes.

Impact
Arbitrary JS in admin CP; session/CSRF token theft; potential full admin takeover via DOM-driven actions.

Remediation

• Sanitize/HTML-encode all user-controlled strings before passing to dangerouslySetInnerHTML, or avoid it for labels/titles/icons.
• Server-side: strip/escape disallowed tags on save for fields, integration metadata, WYSIWYG content.
• Add regression tests with <img onerror> payloads to ensure no execution in builder/integration views.

Workarounds

• Restrict form-edit permissions to trusted admins only until patched.
• Consider CSP that disallows inline scripts (defense-in-depth only).

Credits

• Discovered by https://www.linkedin.com/in/praveenkavinda/ | Prav33N-Sec.

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

Kodem intelligence

1. What is CVE-2026-26188? CVE-2026-26188 is a low-severity cross-site scripting (XSS) vulnerability in solspace/craft-freeform (composer), affecting versions >= 5.0.0, <= 5.14.6. It is fixed in 5.14.7. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. Which versions of solspace/craft-freeform are affected by CVE-2026-26188? solspace/craft-freeform (composer) versions >= 5.0.0, <= 5.14.6 is affected.
3. Is there a fix for CVE-2026-26188? Yes. CVE-2026-26188 is fixed in 5.14.7. Upgrade to this version or later.
4. Is CVE-2026-26188 exploitable, and should I be worried? Whether CVE-2026-26188 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether CVE-2026-26188 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix CVE-2026-26188? Upgrade solspace/craft-freeform to 5.14.7 or later.