Description
Silverstripe UserForms provides a visual form builder for the Silverstripe CMS. From 6.0.0 until 6.4.9, 7.0.7, and 7.1.1, the userform email recipient subject field in the CMS accepts a specially crafted payload that can be interpreted as executable server-side code. An authenticated CMS user with permission to configure a UserForms email recipient can use the subject field to run arbitrary code on the server, compromising confidentiality, integrity, and availability. This issue is fixed in versions 6.4.9, 7.0.7, and 7.1.1.
References8
- github.com/silverstripe/silverstripe-userforms/commit/23c069866…
- github.com/silverstripe/silverstripe-userforms/commit/c55494ad7…
- github.com/silverstripe/silverstripe-userforms/pull/1441
- github.com/silverstripe/silverstripe-userforms/pull/1442
- github.com/silverstripe/silverstripe-userforms/releases/tag/6.4…
- github.com/silverstripe/silverstripe-userforms/releases/tag/7.0…
- github.com/silverstripe/silverstripe-userforms/releases/tag/7.1…
- github.com/silverstripe/silverstripe-userforms/security/advisor…
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 55 · as of 8 November 2026
- CWE
- CWE-94
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.