CVE-2026-28783

Craft has a Twig Function Blocklist Bypass

State: Published
Severity: 9.4 Critical
Published: Mar 4, 2026
Updated: Mar 6, 2026
Reserved: Mar 3, 2026

Description

Craft is a content management system (CMS). Prior to 5.9.0-beta.1 and 4.17.0-beta.1, Craft CMS implements a blocklist to prevent potentially dangerous PHP functions from being called via Twig non-Closure arrow functions. In order to be able to successfully execute this attack, you need to either have allowAdminChanges enabled on production, or a compromised admin account, or an account with access to the System Messages utility. Several PHP functions are not included in the blocklist, which could allow malicious actors with the required permissions to execute various types of payloads, including RCEs, arbitrary file reads, SSRFs, and SSTIs. This vulnerability is fixed in 5.9.0-beta.1 and 4.17.0-beta.1.

Scores

CVSS	Score	Vector	Source
4.0	9.4 Critical	CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H	GitHub_M

Weaknesses

CWE-94 Improper Control of Generation of Code ('Code Injection')
CWE-184 Incomplete List of Disallowed Inputs
CWE-1336 Improper Neutralization of Special Elements Used in a Template Engine

Affected Products

Product	Versions
cmscraftcms	>= 5.0.0-RC1, <= 5.9.0-beta.1Affected >= 4.0.0-RC1, <= 4.17.0-beta.1Affected

References

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