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.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54721.json",
"cwe_ids": [
"CWE-94"
],
"cna_assigner": "GitHub_M"
}{
"source": [
"AFFECTED_FIELD",
"REFERENCES"
],
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "6.4.9"
},
{
"introduced": "7.0.0"
},
{
"fixed": "7.0.7"
},
{
"introduced": "7.1.0"
},
{
"fixed": "7.1.1"
}
]
}