Description
Craft is a platform for creating digital experiences. Versions 5.0.0-RC1 through 5.8.20 and 4.0.0-RC1 through 4.16.16 are vulnerable to potential authenticated Remote Code Execution via malicious attached Behavior. Note that attackers must have administrator access to the Craft Control Panel for this to work. Users should update to the patched versions (5.8.21 and 4.16.17) to mitigate the issue.
Affected products
craftcms: craft cms
References6
- github.com/craftcms/cms/security/advisories/GHSA-255j-qw47-wjh5 ExploitVendor Advisory
- github.com/craftcms/cms/security/advisories/GHSA-255j-qw47-wjh5 ExploitVendor Advisory
- github.com/craftcms/cms/commit/27f55886098b56c00ddc53b69239c9c9… Patch
- github.com/craftcms/cms/commit/6e608a1a5bfb36943f94f584b7548ca5… Patch
- github.com/craftcms/cms/commit/ec43c497edde0b2bf2e39a119cded2e5… Patch
- github.com/craftcms/cms/blob/5.x/CHANGELOG.md#5821---2025-12-04 ProductRelease Notes
Metrics
- CVSS 3.1
-
7.2
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - CVSS 4.0
-
8.6
HIGH
Score source: CNA
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:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 62 · as of 11 November 2026
- CWE
- CWE-470
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.