# solspace/craft-freeform Vulnerable to XSS in `PhpSpreadsheet` HTML Writer Due to Unsanitized Styling Data

Source: https://junglewise.ai/threats/solspace-craft-freeform-vulnerable-to-xss-in-phpspreadsheet-html-writer-91c20d91  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-01-15  
License: CC BY 4.0 with a link back

Severity: medium · CVSS 4 · Published 2026-01-15

solspace/craft-freeform Vulnerable to XSS in `PhpSpreadsheet` HTML Writer Due to Unsanitized Styling Data

Technologies: [solspace/craft-freeform (Packagist)](https://junglewise.ai/threats/technologies/solspace-craft-freeform). Vendors: [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Medium severity, with a CVSS score of 4, published 15 January 2026.

**Which products and versions are affected?** solspace/craft-freeform (Packagist) ECOSYSTEM:introduced=0,fixed=4.1.23.

**Is there a fix for This vulnerability?** Yes. solspace/craft-freeform (Packagist): upgrade to 4.1.23 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected?** Check whether you run solspace/craft-freeform (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- solspace/craft-freeform (Packagist): upgrade to 4.1.23 or later

  ```sh
  composer require solspace/craft-freeform:^4.1.23
  ```


## Affected products

- solspace/craft-freeform (Packagist) ECOSYSTEM:introduced=0,fixed=4.1.23

## Related threats

- [Solspace Freeform Twig template injection via form field values](https://junglewise.ai/threats/cve-2026-73858-solspace-freeform-twig-template-injection-via-form-field-values)
- [Freeform Craft Plugin CP UI (builder/integrations) has Stored Cross-Site Scripting (XSS) issue](https://junglewise.ai/threats/cve-2026-26188-freeform-craft-plugin-cp-ui-builder-integrations-has-stored-cross)
- [solspace/craft-freeform Exposed to Known Axios Vulnerabilities via Precompiled Assets](https://junglewise.ai/threats/solspace-craft-freeform-exposed-to-known-axios-vulnerabilities-via-4729a168)
- [solspace/craft-freeform Has a DoS Vulnerability](https://junglewise.ai/threats/solspace-craft-freeform-has-a-dos-vulnerability-b273aed2)
- [The Freeform CraftCMS plugin contains an Server-side template injection (SSTI) vulnerability](https://junglewise.ai/threats/cve-2025-52122-the-freeform-craftcms-plugin-contains-an-server-side-template)