A Server-side Template Injection (SSTI) vulnerability exists in Nystudio107 Seomatic…
Priority MEDIUM 45CWE-94Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- 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 · NVD. Fix status from CNA and GitHub. Impact type from CWE-94.
Summary
A Server-side Template Injection (SSTI) vulnerability exists in Nystudio107 Seomatic 3.4.12 in src/helpers/UrlHelper.php via the host header.
Why it matters now
EPSS 0.01395 72nd percentileScored 2026-11-07
Fix Fixed nystudio107/craft-seomatic (Packagist): 3.4.12
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | nystudio107/craft-seomatic (Packagist) | before 3.4.12 | 3.4.12 | Patch available | GHSA-m3xv-x3ph-mq22 |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- nystudio107/craft-seomatic (Packagist) Vendor— Affected before 3.4.12 Fixed in 3.4.12 Patch available GHSA-m3xv-x3ph-mq22
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:nystudio107:seomatic:3.4.12:*:*:*:*:craft_cms:*:* | 3.4.12 | Vulnerable | Nystudio107 |
- cpe:2.3:a:nystudio107:seomatic:3.4.12:*:*:*:*:craft_cms:*:* Versions 3.4.12 Vulnerable ·Nystudio107
Remediation
- Fix · GHSA-m3xv-x3ph-mq22 nystudio107/craft-seomatic (Packagist) Fixed in 3.4.12 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2021-44618
- 2026-10-03 Alias added: GHSA-m3xv-x3ph-mq22
References
More Nystudio107 Seomatic vulnerabilities
- TI-2021-18401 In the SEOmatic plugin up to 3.4.11 for Craft CMS 3, it is possible for unauthenticated… CVSS 3.1CRITICAL 9.8
- TI-2018-10569 A Server Side Template Injection (SSTI) was discovered in the SEOmatic plugin before… CVSS 3.1HIGH 7.5
- TI-2020-10174 In the SEOmatic plugin before 3.2.49 for Craft CMS, helpers/DynamicMeta.php does not… CVSS 3.1HIGH 7.5
- TI-2021-18402 A cross-site scripting (XSS) vulnerability in the SEOmatic plugin 3.4.10 for Craft CMS 3… CVSS 3.1MEDIUM 6.1
Sources
- CVE-2021-44618 · CVE Program
- CVE-2021-44618 · NVD
- FIRST EPSS
- GHSA-m3xv-x3ph-mq22 · 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