CVE-2026-26067

October: Safe Mode Bypass via CSS Preprocessor Compilers

State: Published
Severity: 4.9 Medium
Published: Apr 21, 2026
Updated: Apr 21, 2026
Reserved: Feb 10, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	4.9 Medium	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N	GitHub_M

Weaknesses

CWE-863 Incorrect Authorization
CWE-184 Incomplete List of Disallowed Inputs

Affected Products

Product	Versions
octoberoctobercms	>= 4.0.0, < 4.1.10Affected < 3.7.14Affected

References

https://github.com/octobercms/october/security/advisories/GHSA-3888-q23f-x7qh

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