How severe is CVE-2021-41502?

CVE-2021-41502 has a CVSS score of 5.4/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-41502?

CVE-2021-41502 affects the following packages: intelliants/subrion (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2021-41502?

The records we use list no patched version of intelliants/subrion for CVE-2021-41502. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.

How do I detect CVE-2021-41502 in my Packagist dependencies?

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

How do I mitigate CVE-2021-41502 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-2021-41502 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2021-41502, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-41502?

CVE-2021-41502 has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 47th 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-2021-41502?

CVE-2021-41502 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-2021-41502 published, and has it been updated?

CVE-2021-41502 was published on June 11, 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-2021-41502 — subrion

MEDIUM

CVE-2021-41502 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in intelliants/subrion. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

Cross site scripting in intelliants/subrion

Also known asGHSA-jvq4-cgfw-jgf4

Published

Jun 11, 2022

Updated

Oct 20, 2026

Affected

1 pkg

Patched

See advisory

Exploits

1 known

Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs47th percentile — riskier than 47% 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

🐘intelliants/subrion

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

An issue was discovered in Subrion CMS v4.2.1 There is a stored cross-site scripting (XSS) vulnerability that can execute malicious JavaScript code by modifying the name of the uploaded image, closing the html tag, or adding the onerror attribute.

Affected Packages

1 total

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`intelliants/subrion`	all versions	No fix

Affected Products

1 product · 1 configurations

Application

subrion cmsintelliants

1 version

4.2.1

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

An issue was discovered in Subrion CMS v4.2.1 There is a stored cross-si…

github.comNVDJun 2022

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for intelliants/subrion, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of intelliants/subrion for CVE-2021-41502. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
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-2021-41502 in your dependencies?

Find it across Packagist, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

5.4/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Raw vector

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

CWE Classification

CWE-79Cross-site Scripting (XSS)

Weaponization

No Nuclei template or Metasploit module yet. 1 public proof-of-concept reference is listed on this page.

OpenSSF Scorecard

Package health score

subrion

3.9/10

Code-Review9/10

Maintained0/10

Branch-ProtectionN/A

Assessed Nov 2, 2026

Timeline

Disclosed

Jun 11, 2022

First exploit

Jun 17, 2022

6 days after disclosure — rapid exploitation

Last updated

Oct 20, 2026

Identifiers

CVE-2021-41502

GHSA-jvq4-cgfw-jgf4

References

Advisorynvd.nist.gov · CVE 2021 41502 Packagegithub.com · subrion Evidencegithub.com

Related vulnerabilities

This CVE is medium severity; 7 of 8 other CVEs affecting intelliants/subrion are rated as high or higher (top: high).

CVE-2026-12202CVE-2025-70958CVE-2025-56556CVE-2024-25399CVE-2023-46947CVE-2023-43875CVE-2023-43884CVE-2023-43828

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 20, 2026