How severe is CVE-2021-41750?

CVE-2021-41750 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-41750?

CVE-2021-41750 affects the following packages: nystudio107/craft-seomatic (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2021-41750?

Update nystudio107/craft-seomatic to 3.4.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-41750 is resolved across your whole dependency graph.

How do I detect CVE-2021-41750 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nystudio107/craft-seomatic, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-41750 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2021-41750 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-41750 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-41750?

CVE-2021-41750 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 66th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-41750?

CVE-2021-41750 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2021-41750 published, and has it been updated?

CVE-2021-41750 was published on June 12, 2022 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘

🐘 Packagist

Not in CISA KEV

MEDIUM severity

CVE-2021-41750 — craft-seomatic

MEDIUMFix: nystudio107/craft-seomatic@4e46b79

CVE-2021-41750 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in nystudio107/craft-seomatic. A fix is available for nystudio107/craft-seomatic — see the affected versions and patch details below.

Cross-site Scripting in SEOmatic plugin

Also known asGHSA-6hjc-m38h-7jhh

Published

Jun 12, 2022

Updated

Oct 20, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.1%probability of exploitation in next 30 days

Lower Risk+0.04%

Lower risk than most CVEs66th percentile — riskier than 66% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐘nystudio107/craft-seomatic

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

A cross-site scripting (XSS) vulnerability in the SEOmatic plugin 3.4.10 for Craft CMS 3 allows remote attackers to inject arbitrary web script via a GET to /index.php?action=seomatic/file/seo-file-link with url parameter containing the base64 encoded URL of a malicious web page / file and fileName parameter containing an arbitrary filename with the intended content-type to be rendered in the user's browser as the extension.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`nystudio107/craft-seomatic`	all versions	3.4.11`composer require nystudio107/craft-seomatic:^3.4.11`

Affected Products

1 product · 1 configurations

Application

seomaticnystudio107

1 version

3.4.10

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nystudio107/craft-seomatic, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update nystudio107/craft-seomatic to 3.4.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-41750 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-41750 in your dependencies?

Find it across Packagist, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

6.1/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CWE Classification

CWE-79Cross-site Scripting (XSS)

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

Timeline

Disclosed

Jun 12, 2022

Last updated

Oct 20, 2026

Identifiers

CVE-2021-41750

GHSA-6hjc-m38h-7jhh

References

Advisorygithub.com · CHANGELOG.md Advisorynvd.nist.gov · CVE 2021 41750 Fixgithub.com · 4e46b792ce973ac0c652fb330055f41aca1981c8 Fixgithub.com · 5f2cdc7c39e0a4bfb60d2f84131508f0a87b2873 Packagegithub.com · craft seomatic

Related vulnerabilities

Also affects nystudio107/craft-seomatic

This CVE is medium severity; 5 of 5 other CVEs affecting nystudio107/craft-seomatic are rated as high or higher (top: critical).

CVE-2021-41749CVE-2020-12790CVE-2020-9757CVE-2018-14716CVE-2021-44618

Same weakness: CWE-79

This CVE is medium severity; 3 of 3 other CVEs with CWE-79 are rated as high or higher (top: critical).

CVE-2026-113787CVE-2026-44267CVE-2026-96632Browse all CWE-79

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 20, 2026