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.

References

https://github.com/silverstripe/silverstripe-userforms/security/advisories/GHSA-g8wr-r2v2-vqc6

https://github.com/silverstripe/silverstripe-userforms/releases/tag/7.1.1

https://github.com/silverstripe/silverstripe-userforms/releases/tag/7.0.7

https://github.com/silverstripe/silverstripe-userforms/releases/tag/6.4.9

https://github.com/silverstripe/silverstripe-userforms/pull/1442

https://github.com/silverstripe/silverstripe-userforms/pull/1441

https://github.com/silverstripe/silverstripe-userforms/commit/c55494ad7c717b199a3c1663b43a54db5d95604c

https://github.com/silverstripe/silverstripe-userforms/commit/23c069866900c19b499bfa997d1e251e97491702

Details

Source: Mitre, NVD

Published: 2026-08-27

Updated: 2026-08-28

Risk Information

CVSS v2

Base Score: 9

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C

Severity: High

CVSS v3

Base Score: 8.8

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00415