CVE-2026-54721
High
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.
SeverityHigh
CVSS8.8
Exploit probability—
ProductSilverstripe/userforms
PublishedAug 27, 2026
First seenAug 27, 2026
Weakness typeCWE-94Code injection
How to fix
Update
- silverstripe/userforms6.4.9, 7.0.7, 7.1.1 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| silverstripe/userformsPackagist | v < 6.4.9, 7.0.0 ≤ v < 7.0.7, 7.1.0 ≤ v < 7.1.1 | 6.4.9, 7.0.7, 7.1.1 |
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