CVE-2020-15247: Twig Sandbox Escape by authenticated users with access to editing CMS templates when safemode is enabled.

Severity: medium (CVSS 5.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-11-23 · updated 2026-06-17
Weakness: CWE-862

Description

October is a free, open-source, self-hosted CMS platform based on the Laravel PHP Framework. In October CMS from version 1.0.319 and before version 1.0.469, an authenticated backend user with the cms.manage_pages, cms.manage_layouts, or cms.manage_partials permissions who would normally not be permitted to provide PHP code to be executed by the CMS due to cms.enableSafeMode being enabled is able to write specific Twig code to escape the Twig sandbox and execute arbitrary PHP. This is not a problem for anyone that trusts their users with those permissions to normally write & manage PHP within the CMS by not having cms.enableSafeMode enabled, but would be a problem for anyone relying on cms.enableSafeMode to ensure that users with those permissions in production do not have access to write & execute arbitrary PHP. Issue has been patched in Build 469 (v1.0.469) and v1.1.0.

Affected products

octobercms october: from 1.0.319 before 1.0.469 — fixed in 1.0.469

How to fix

Upgrade to a fixed version: octobercms october 1.0.469. Check the vendor advisory for mitigations.

References

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