# CVE-2026-26067: October CMS has Safe Mode Bypass via CSS Preprocessor Compilers

Source: https://junglewise.ai/threats/cve-2026-26067-october-cms-has-safe-mode-bypass-via-css-preprocessor-compilers  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-21. Updated: 2026-05-11  
License: CC BY 4.0 with a link back

CVE-2026-26067 · Severity: medium · CVSS 4.9 · Published 2026-04-21

October is a Content Management System (CMS) and web platform. Prior to 3.7.14 and 4.1.10, a server-side information disclosure vulnerability was identified in the handling of CSS preprocessor files. Backend users with Editor permissions could craft .less, .sass, or .scss files that leverage the compiler's import functionality to read arbitrary files from the server. This worked even with cms.safe_mode enabled. This vulnerability is fixed in 3.7.14 and 4.1.10.

Technologies: [october/system (Packagist)](https://junglewise.ai/threats/technologies/october-system). Vendors: [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is CVE-2026-26067 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-26067 being exploited in the wild.

**How severe is CVE-2026-26067?** Medium severity, with a CVSS score of 4.9, published 21 April 2026.

**Which products and versions are affected?** october/system (Packagist) ECOSYSTEM:introduced=0,fixed=3.7.14.

**Is there a fix for CVE-2026-26067?** Yes. october/system (Packagist): upgrade to 3.7.14 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-26067?** Check whether you run october/system (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

- october/system (Packagist): upgrade to 3.7.14 or later

  ```sh
  composer require october/system:^3.7.14
  ```


## Affected products

- october/system (Packagist) ECOSYSTEM:introduced=0,fixed=3.7.14

## Identifiers

- CVE-2026-26067
- GHSA-3888-q23f-x7qh

## References

- [https://api.github.com/users/Neosprings](https://api.github.com/users/Neosprings)
- [https://github.com/Neosprings](https://github.com/Neosprings)
- [https://api.github.com/users/Neosprings/gists%7B/gist_id%7D](https://api.github.com/users/Neosprings/gists%7B/gist_id%7D)
- [https://api.github.com/users/Neosprings/repos](https://api.github.com/users/Neosprings/repos)
- [https://avatars.githubusercontent.com/u/149110916?v=4](https://avatars.githubusercontent.com/u/149110916?v=4)
- [https://api.github.com/users/Neosprings/events%7B/privacy%7D](https://api.github.com/users/Neosprings/events%7B/privacy%7D)

## Related threats

- [October CMS PHP object injection in widget session storage](https://junglewise.ai/threats/cve-2026-49400-october-cms-php-object-injection-in-widget-session-storage)
- [October CMS Twig sandbox bypass in Safe Mode](https://junglewise.ai/threats/cve-2026-46696-october-cms-twig-sandbox-bypass-in-safe-mode)
- [October CMS: Editor Sub-Permission Bypass for Asset and Blueprint File Operations](https://junglewise.ai/threats/cve-2026-29179-october-cms-editor-sub-permission-bypass-for-asset-and-blueprint)
- [October CMS: Reflected XSS via DataTable Form Widget](https://junglewise.ai/threats/cve-2026-27937-october-cms-reflected-xss-via-datatable-form-widget)
- [October CMS has Stored XSS in Event Log Mail Preview](https://junglewise.ai/threats/cve-2026-24907-october-cms-has-stored-xss-in-event-log-mail-preview)