How severe is CVE-2021-21030?

CVE-2021-21030 has a CVSS score of 8.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-21030?

CVE-2021-21030 affects the following packages: magento/community-edition (Packagist), magento/community-edition (Packagist), magento/project-community-edition (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2021-21030?

Update magento/community-edition to 2.3.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-21030 is resolved across your whole dependency graph.

How do I detect CVE-2021-21030 in my Packagist dependencies?

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

How do I mitigate CVE-2021-21030 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-2021-21030 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-21030 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-2021-21030?

CVE-2021-21030 has an EPSS (Exploit Prediction Scoring System) score of 5.6%, placing it in the 93th 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-2021-21030?

CVE-2021-21030 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-2021-21030 published, and has it been updated?

CVE-2021-21030 was published on February 11, 2021 and was last updated on October 24, 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

HIGH severity

CVE-2021-21030 — community-edition

HIGH

CVE-2021-21030 is a high-severity (CVSS 8.1) Cross-site Scripting (XSS) vulnerability in magento/community-edition. A fix is available for magento/community-edition — see the affected versions and patch details below.

Magento stored cross-site scripting (XSS) in the customer address upload feature

Also known asBIT-magento-2021-21030GHSA-6988-g89m-27vf

Published

Feb 11, 2021

Updated

Oct 24, 2026

Affected

3 pkgs

Patched

2 / 3

Exploits

None indexed

Exploitation data as of Oct 28, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

5.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs93th percentile — riskier than 93% 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

3 pkgs affected

🐘magento/community-edition🐘magento/community-edition🐘magento/project-community-edition

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

Magento versions 2.4.1 (and earlier), 2.4.0-p1 (and earlier) and 2.3.6 (and earlier) are vulnerable to a stored cross-site scripting (XSS) in the customer address upload feature. Successful exploitation could lead to arbitrary JavaScript execution in the victim's browser. Exploitation of this issue requires user interaction.

Affected Packages

3 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`magento/community-edition`	all versions	2.3.6`composer require magento/community-edition:^2.3.6`
🐘Packagist	`magento/community-edition`	≥ 2.4.0&&< 2.4.1-p1	2.4.1-p1`composer require magento/community-edition:^2.4.1-p1`
🐘Packagist	`magento/project-community-edition`	all versions	No fix

Affected Products

1 product · 10 configurations

Application

magentomagento

< 2.3.6

3 versions

2.3.62.4.02.4.1

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for magento/community-edition, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update magento/community-edition to 2.3.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-21030 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-2021-21030 in your dependencies?

Find it across Packagist, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

8.1/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Raw vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

CWE Classification

CWE-79Cross-site Scripting (XSS)

Weaponization

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

OpenSSF Scorecard

Package health score

magento2

6.2/10

Maintained10/10

Code-Review1/10

Branch-ProtectionN/A

Assessed Oct 26, 2026

Timeline

Disclosed

Feb 11, 2021

Last updated

Oct 24, 2026

Identifiers

CVE-2021-21030

GHSA-6988-g89m-27vf

BIT-magento-2021-21030

References

Advisoryhelpx.adobe.com · apsb21 08 Advisorynvd.nist.gov · CVE 2021 21030 Packagegithub.com · magento2

Related vulnerabilities

This CVE is high severity; 5 of 8 other CVEs affecting magento/community-edition are rated as high or higher (top: critical).

CVE-2025-54264CVE-2025-54263CVE-2025-54266CVE-2025-54267CVE-2025-54265CVE-2025-54236CVE-2025-49555CVE-2025-49556

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 24, 2026