---
id: CVE-2026-63179
title: Winter CMS is a content management system built on the Laravel PHP framework
summary: >-
  Winter CMS is a content management system built on the Laravel PHP framework.
  In versions up to and including 1.2.12, authenticated backend users can
  disclose arbitrary files readable by the PHP process by injecting @import
  (inline) dire…
severity: medium
cvss: 4.9
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-22
vendor: winter
product: winter/wn-backend-module
affected:
  - winter/wn-backend-module <= 1.2.12
patched:
  - winter/wn-backend-module 1.2.13
published: '2026-08-26'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:09:13.080'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-63179'
references:
  - url: >-
      https://github.com/wintercms/storm/commit/af770331c683e628533a6ec2991285d6e10a4d6c
    label: security-advisories@github.com
  - url: >-
      https://github.com/wintercms/winter/commit/130f0ea43e9228bf0d129b481da1cdfbcc4b4456
    label: security-advisories@github.com
  - url: 'https://github.com/wintercms/winter/releases/tag/v1.2.13'
    label: security-advisories@github.com
  - url: >-
      https://github.com/wintercms/winter/security/advisories/GHSA-58fp-mcx6-7qf9
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-58fp-mcx6-7qf9'
tags:
  - nvd
  - ghsa
  - composer
epss: 0.00515
epssPercentile: 0.4138
aliases:
  - GHSA-58fp-mcx6-7qf9
ecosystem: composer
ingestedAt: '2026-08-20T18:59:53.748Z'
---

## Overview

Winter CMS is a content management system built on the Laravel PHP framework. In versions up to and including 1.2.12, authenticated backend users can disclose arbitrary files readable by the PHP process by injecting @import (inline) directives into LESS source that the backend compiles, because the LESS parser was instantiated without a safe import resolver and fell back to the raw attacker-supplied path when no allowed root matched. The flaw is reachable through four entry points that share the same root cause: the Brand Settings custom_css field, the Editor Settings html_custom_styles field, the Mail Brand Settings colour-picker fields whose values are concatenated into LESS source without escaping, and theme .less, .sass, and .scss assets compiled when served. Both absolute paths and .. traversal outside the asset's own tree were accepted, so an attacker could read any file the web process can access, most significantly the application .env file and the APP_KEY and database credentials it contains. Exploitation requires a backend account holding one of the associated permissions, which are assigned by default to the built-in Developer role. This issue is fixed in version 1.2.13.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-63179)

Affected packages:

- `winter/wn-backend-module <= 1.2.12`

Patched in:

- `winter/wn-backend-module 1.2.13`

Source: https://github.com/advisories/GHSA-58fp-mcx6-7qf9