Incomplete List of Disallowed Inputs in Craft CMS - CVE-2026-28783
Published: June 16, 2026
Vulnerability identifier: #VU134654
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-28783
CWE-ID: CWE-184
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Pixel & Tonic, Inc.
Affected software:
Craft CMS
Craft CMS
Detailed vulnerability description
The vulnerability allows a remote user to execute arbitrary code, read arbitrary files, perform server-side request forgery, or conduct server-side template injection.
The vulnerability exists due to incomplete list of disallowed inputs in Twig non-Closure arrow functions when processing crafted template expressions. A remote user can invoke blocklisted-bypass PHP functions to execute arbitrary code, read arbitrary files, perform server-side request forgery, or conduct server-side template injection.
Exploitation requires either `allowAdminChanges` to be enabled on production, a compromised admin account, or access to the System Messages utility.
How to mitigate CVE-2026-28783
Install security update from vendor's website.