CVE-2026-54721
Medium
Elevated severity or exploit probability.
CVSS base
8.8
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
0.7%
52.4th percentile
CISA KEV
Not listed
Weakness / dates
CWE-94
Published 2026-08-27 · modified 2026-09-09
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/commit/23c069866900c19b499bfa997d1e251e97491702
- https://github.com/silverstripe/silverstripe-userforms/commit/c55494ad7c717b199a3c1663b43a54db5d95604c
- https://github.com/silverstripe/silverstripe-userforms/pull/1441
- https://github.com/silverstripe/silverstripe-userforms/pull/1442
- https://github.com/silverstripe/silverstripe-userforms/releases/tag/6.4.9
- https://github.com/silverstripe/silverstripe-userforms/releases/tag/7.0.7
- https://github.com/silverstripe/silverstripe-userforms/releases/tag/7.1.1
- https://github.com/silverstripe/silverstripe-userforms/security/advisories/GHSA-g8wr-r2v2-vqc6