silverstripe/userforms vulnerable to remote code execution via userforms email subject
The advisory, in context
Impact
The userform email subject field in the CMS is vulnerable to a specially crafted payload being used to run arbitrary code on the server.
Reported by
Jack Wallace from Bastion Security
Affected packages
Start with the recorded fix for your release branch. Check your installed version and test compatibility before upgrading. Fixing this advisory does not rule out other vulnerabilities in the release.
Earlier releases before 6.4.9
Fixed in 6.4.9
172 explicitly affected versions
0.5.1, 1.0.1, 1.1.0-beta, 2.0.1, 2.0.1-rc1, 2.0.10, 2.0.2, 2.0.3, 2.0.4, 2.0.5, 2.0.6, 2.0.7, 2.0.8, 2.0.9, 3.0.0, 3.0.0-beta1, 3.0.1, 3.0.2, 3.1.0, 3.1.1, 3.1.2, 4.0.0, 4.0.1, 4.1.0, 4.2.0, 4.2.1, 4.2.2, 4.2.3, 4.2.4, 4.2.5, 4.2.6, 4.3.0, 4.3.1, 4.3.2, 4.3.3, 4.3.4, 4.3.5, 4.4.0, 4.4.1, 4.4.2, 4.5.0, 4.5.1, 4.5.2, 4.5.3, 4.5.4, 4.5.5, 4.5.6, 4.5.7, 4.5.8, 4.6.0, 4.6.1, 4.6.2, 4.6.3, 5.0.0, 5.0.0-beta1, 5.0.0-beta2, 5.0.1, 5.0.2, 5.1.0, 5.1.1, 5.10.0, 5.10.0-alpha1, 5.10.0-beta1, 5.10.0-rc1, 5.11.0, 5.11.1, 5.12.0, 5.12.1, 5.12.2, 5.13.0, 5.13.0-beta1, 5.13.0-rc1, 5.13.1, 5.13.2, 5.13.3, 5.13.4, 5.14.0, 5.14.0-beta1, 5.14.0-rc1, 5.14.1, 5.14.2, 5.14.3, 5.15.0, 5.15.0-beta1, 5.15.0-rc1, 5.15.1, 5.15.10, 5.15.11, 5.15.2, 5.15.3, 5.15.4, 5.15.5, 5.15.6, 5.15.7, 5.15.8, 5.15.9, 5.2.0, 5.2.1, 5.2.2, 5.3.0, 5.3.1, 5.3.2, 5.3.3, 5.4.0, 5.4.1, 5.4.2, 5.4.3, 5.5.0, 5.5.1, 5.5.2, 5.5.3, 5.6.0, 5.6.0-rc1, 5.6.1, 5.6.2, 5.6.3, 5.7.0, 5.7.1, 5.8.0, 5.8.1, 5.8.2, 5.8.3, 5.9.0, 5.9.0-beta1, 5.9.0-rc1, 5.9.1, 6.0.0, 6.0.0-beta1, 6.0.0-rc1, 6.0.1, 6.0.2, 6.0.3, 6.0.4, 6.0.5, 6.0.6, 6.0.7, 6.0.8, 6.1.0, 6.1.0-beta1, 6.1.0-rc1, 6.1.1, 6.1.2, 6.2.0, 6.2.0-beta1, 6.2.0-rc1, 6.2.1, 6.2.10, 6.2.2, 6.2.3, 6.2.4, 6.2.5, 6.2.6, 6.2.7, 6.2.8, 6.2.9, 6.3.0, 6.3.0-beta1, 6.3.0-rc1, 6.3.1, 6.3.2, 6.4.0, 6.4.0-beta1, 6.4.0-rc1, 6.4.1, 6.4.2, 6.4.3, 6.4.4, 6.4.5, 6.4.6, 6.4.7, 6.4.8, v5.9.2
View affected-version evidence
{
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "6.4.9"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"0.5.1",
"1.0.1",
"1.1.0-beta",
"2.0.1",
"2.0.1-rc1",
"2.0.10",
"2.0.2",
"2.0.3",
"2.0.4",
"2.0.5",
"2.0.6",
"2.0.7",
"2.0.8",
"2.0.9",
"3.0.0",
"3.0.0-beta1",
"3.0.1",
"3.0.2",
"3.1.0",
"3.1.1",
"3.1.2",
"4.0.0",
"4.0.1",
"4.1.0",
"4.2.0",
"4.2.1",
"4.2.2",
"4.2.3",
"4.2.4",
"4.2.5",
"4.2.6",
"4.3.0",
"4.3.1",
"4.3.2",
"4.3.3",
"4.3.4",
"4.3.5",
"4.4.0",
"4.4.1",
"4.4.2",
"4.5.0",
"4.5.1",
"4.5.2",
"4.5.3",
"4.5.4",
"4.5.5",
"4.5.6",
"4.5.7",
"4.5.8",
"4.6.0",
"4.6.1",
"4.6.2",
"4.6.3",
"5.0.0",
"5.0.0-beta1",
"5.0.0-beta2",
"5.0.1",
"5.0.2",
"5.1.0",
"5.1.1",
"5.10.0",
"5.10.0-alpha1",
"5.10.0-beta1",
"5.10.0-rc1",
"5.11.0",
"5.11.1",
"5.12.0",
"5.12.1",
"5.12.2",
"5.13.0",
"5.13.0-beta1",
"5.13.0-rc1",
"5.13.1",
"5.13.2",
"5.13.3",
"5.13.4",
"5.14.0",
"5.14.0-beta1",
"5.14.0-rc1",
"5.14.1",
"5.14.2",
"5.14.3",
"5.15.0",
"5.15.0-beta1",
"5.15.0-rc1",
"5.15.1",
"5.15.10",
"5.15.11",
"5.15.2",
"5.15.3",
"5.15.4",
"5.15.5",
"5.15.6",
"5.15.7",
"5.15.8",
"5.15.9",
"5.2.0",
"5.2.1",
"5.2.2",
"5.3.0",
"5.3.1",
"5.3.2",
"5.3.3",
"5.4.0",
"5.4.1",
"5.4.2",
"5.4.3",
"5.5.0",
"5.5.1",
"5.5.2",
"5.5.3",
"5.6.0",
"5.6.0-rc1",
"5.6.1",
"5.6.2",
"5.6.3",
"5.7.0",
"5.7.1",
"5.8.0",
"5.8.1",
"5.8.2",
"5.8.3",
"5.9.0",
"5.9.0-beta1",
"5.9.0-rc1",
"5.9.1",
"6.0.0",
"6.0.0-beta1",
"6.0.0-rc1",
"6.0.1",
"6.0.2",
"6.0.3",
"6.0.4",
"6.0.5",
"6.0.6",
"6.0.7",
"6.0.8",
"6.1.0",
"6.1.0-beta1",
"6.1.0-rc1",
"6.1.1",
"6.1.2",
"6.2.0",
"6.2.0-beta1",
"6.2.0-rc1",
"6.2.1",
"6.2.10",
"6.2.2",
"6.2.3",
"6.2.4",
"6.2.5",
"6.2.6",
"6.2.7",
"6.2.8",
"6.2.9",
"6.3.0",
"6.3.0-beta1",
"6.3.0-rc1",
"6.3.1",
"6.3.2",
"6.4.0",
"6.4.0-beta1",
"6.4.0-rc1",
"6.4.1",
"6.4.2",
"6.4.3",
"6.4.4",
"6.4.5",
"6.4.6",
"6.4.7",
"6.4.8",
"v5.9.2"
]
}From 7.0.0 before 7.0.7
Fixed in 7.0.7
7 explicitly affected versions
7.0.0, 7.0.1, 7.0.2, 7.0.3, 7.0.4, 7.0.5, 7.0.6
View affected-version evidence
{
"ranges": [
{
"events": [
{
"introduced": "7.0.0"
},
{
"fixed": "7.0.7"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"7.0.0",
"7.0.1",
"7.0.2",
"7.0.3",
"7.0.4",
"7.0.5",
"7.0.6"
]
}From 7.1.0 before 7.1.1
Fixed in 7.1.1
1 explicitly affected versions
7.1.0
View affected-version evidence
{
"ranges": [
{
"events": [
{
"introduced": "7.1.0"
},
{
"fixed": "7.1.1"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"7.1.0"
]
}References
- https://github.com/silverstripe/silverstripe-userforms/security/advisories/GHSA-g8wr-r2v2-vqc6
- https://github.com/silverstripe/silverstripe-userforms/pull/1441
- https://github.com/silverstripe/silverstripe-userforms/pull/1442
- https://github.com/silverstripe/silverstripe-userforms/commit/23c069866900c19b499bfa997d1e251e97491702
- https://github.com/silverstripe/silverstripe-userforms/commit/c55494ad7c717b199a3c1663b43a54db5d95604c
- https://github.com/FriendsOfPHP/security-advisories/blob/master/silverstripe/userforms/CVE-2026-54721.yaml
- https://github.com/silverstripe/silverstripe-userforms
- 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://www.silverstripe.org/download/security-releases/cve-2026-54721