CVE-2021-44618
Server-side Template Injection in nystudio107/craft-seomatic
A Server-side Template Injection (SSTI) vulnerability exists in Nystudio107 Seomatic 3.4.12 in src/helpers/UrlHelper.php via the host header.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
A Server-side Template Injection (SSTI) vulnerability exists in Nystudio107 Seomatic 3.4.12 in src/helpers/UrlHelper.php via the host header.
- Record
CVE-2021-44618- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-94
- Updated
- 2026-11-02
CVE List No score
A Server-side Template Injection (SSTI) vulnerability exists in Nystudio107 Seomatic 3.4.12 in src/helpers/UrlHelper.php via the host header.
- Record
CVE-2021-44618- Updated
- 2026-11-02
EUVDEUVD-2022-1466 No score
A Server-side Template Injection (SSTI) vulnerability exists in Nystudio107 Seomatic 3.4.12 in src/helpers/UrlHelper.php via the host header.
- Record
EUVD-2022-1466- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-m3xv-x3ph-mq22
Server-side Template Injection in nystudio107/craft-seomatic
A Server-side Template Injection (SSTI) vulnerability exists in Nystudio107 Seomatic prior to 3.4.12 in src/helpers/UrlHelper.php via the host header.
- Record
GHSA-m3xv-x3ph-mq22- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-94
- Updated
- 2026-11-02
OSV
A Server-side Template Injection (SSTI) vulnerability exists in Nystudio107 Seomatic 3.4.12 in src/helpers/UrlHelper.php via the host header.
- Record
CVE-2021-44618- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-m3xv-x3ph-mq22
Server-side Template Injection in nystudio107/craft-seomatic
A Server-side Template Injection (SSTI) vulnerability exists in Nystudio107 Seomatic prior to 3.4.12 in src/helpers/UrlHelper.php via the host header.
- Record
GHSA-m3xv-x3ph-mq22- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-94
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
nystudio107/craft-seomaticPackagist |
before 3.4.12 | 3.4.12 |
nystudio107/craft-seomaticPackagist |
before 3.4.12, plus listed versions 3.0.03.0.0-beta.13.0.0-beta.103.0.0-beta.113.0.0-beta.12 Show 45 moreShow less3.0.0-beta.133.0.0-beta.143.0.0-beta.153.0.0-beta.163.0.0-beta.173.0.0-beta.183.0.0-beta.193.0.0-beta.23.0.0-beta.203.0.0-beta.213.0.0-beta.223.0.0-beta.233.0.0-beta.243.0.0-beta.33.0.0-beta.43.0.0-beta.53.0.0-beta.63.0.0-beta.73.0.0-beta.83.0.0-beta.93.0.13.0.103.0.113.0.123.0.133.0.143.0.153.0.163.0.173.0.183.0.23.0.203.0.223.0.233.0.243.0.253.0.33.0.43.0.53.0.63.0.73.0.83.0.93.1.03.1.1 |
3.4.12 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-44618 is a critical vulnerability (CVSS 9.8) in Nystudio107 Seomatic, published March 11, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.40%, the 72nd percentile. Fixed in nystudio107/craft-seomatic 3.4.12.
References
Left out here: 161 versions. The JSON record has them.