Silverstripe UserForms: Remote code execution via userforms email subject
Priority MEDIUM 41CWE-94Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-94.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00733 54th percentileScored 2026-11-07
Fix Fixed silverstripe-userforms (silverstripe): 6.4.9, 7.0.7, 7.1.1silverstripe/userforms (Packagist): 6.4.9, 7.0.7, 7.1.1
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| silverstripe | silverstripe-userforms | before 6.4.9; 7.0.0 to before 7.0.7; 7.1.0 to before 7.1.1 | 6.4.9, 7.0.7, 7.1.1 | Patch available | CNA |
| — | silverstripe/userforms (Packagist) | before 6.4.9 | 6.4.9 | Patch available | GHSA-g8wr-r2v2-vqc6 |
| — | silverstripe/userforms (Packagist) | 7.0.0 to before 7.0.7 | 7.0.7 | Patch available | GHSA-g8wr-r2v2-vqc6 |
| — | silverstripe/userforms (Packagist) | 7.1.0 to before 7.1.1 | 7.1.1 | Patch available | GHSA-g8wr-r2v2-vqc6 |
- silverstripe-userforms Vendorsilverstripe Affected before 6.4.9; 7.0.0 to before 7.0.7; 7.1.0 to before 7.1.1 Fixed in 6.4.9, 7.0.7, 7.1.1 Patch available CNA
- silverstripe/userforms (Packagist) Vendor— Affected before 6.4.9 Fixed in 6.4.9 Patch available GHSA-g8wr-r2v2-vqc6
- silverstripe/userforms (Packagist) Vendor— Affected 7.0.0 to before 7.0.7 Fixed in 7.0.7 Patch available GHSA-g8wr-r2v2-vqc6
- silverstripe/userforms (Packagist) Vendor— Affected 7.1.0 to before 7.1.1 Fixed in 7.1.1 Patch available GHSA-g8wr-r2v2-vqc6
Remediation
- Fix · CNA silverstripe-userforms (silverstripe) Fixed in 6.4.9, 7.0.7, 7.1.1
- Fix · GHSA-g8wr-r2v2-vqc6 silverstripe/userforms (Packagist) Fixed in 6.4.9 Advisory →
- Fix · GHSA-g8wr-r2v2-vqc6 silverstripe/userforms (Packagist) Fixed in 7.0.7 Advisory →
- Fix · GHSA-g8wr-r2v2-vqc6 silverstripe/userforms (Packagist) Fixed in 7.1.1 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-54721
- 2026-10-03 Alias added: GHSA-g8wr-r2v2-vqc6
References
Other 11
- 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/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/FriendsOfPHP/security-advisories/blob/master/silverstripe/userforms/CVE-2026-54721.yaml
- https://github.com/silverstripe/silverstripe-userforms
- https://www.silverstripe.org/download/security-releases/cve-2026-54721
More silverstripe vulnerabilities
- TI-2007-02239 Unspecified vulnerability in the search functionality in SilverStripe 2.0.0 has unknown impact and attack vectors. CVSS 2.0HIGH 10.0
- TI-2019-09110 In SilverStripe through 4.3.3, a missing warning about leaving install.php in a public… CVSS 3.1CRITICAL 9.8
- TI-2019-09070 SQL injection vulnerability in silverstripe/restfulserver module 1.0.x before 1.0.9… CVSS 3.0CRITICAL 9.8
- TI-2019-04049 All versions of SilverStripe 3 prior to 3.6.7 and 3.7.3, and all versions of SilverStripe… CVSS 3.0CRITICAL 9.8
- TI-2022-17852 Silverstripe silverstripe/framework through 4.11 allows SQL Injection. CVSS 3.1HIGH 8.8
- TI-2020-07444 Silverstripe CMS through 4.5 can be susceptible to script execution from malicious upload… CVSS 3.1HIGH 8.8
Sources
- CVE-2026-54721 · CVE Program
- CVE-2026-54721 · NVD
- FIRST EPSS
- GHSA-g8wr-r2v2-vqc6 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences