Is CVE-2021-21264 actively exploited?

No active exploitation of CVE-2021-21264 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-21264 be exploited remotely?

No. CVE-2021-21264 requires local access to exploit.

What is the CVSS score of CVE-2021-21264?

CVE-2021-21264 has a CVSS score of 5.2 (MEDIUM).

HOME VULNERABILITIESCVE-2021-21264

MEDIUM

CVE-2021-21264

CWE-862Published: May 3, 2021· Updated: Jun 17, 2026

5.2

CVSS v3.1

Official Description

October is a free, open-source, self-hosted CMS platform based on the Laravel PHP Framework. A bypass of CVE-2020-26231 (fixed in 1.0.470/471 and 1.1.1) was discovered that has the same impact as CVE-2020-26231 & CVE-2020-15247. 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 472 (v1.0.472) and v1.1.2. As a workaround, apply https://github.com/octobercms/october/commit/f63519ff1e8d375df30deba63156a2fc97aa9ee7 to your installation manually if unable to upgrade to Build 472 or v1.1.2.

NVD Source

Technical Analysis

CVE-2021-21264 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.