How severe is CVE-2021-21031?

CVE-2021-21031 has a CVSS score of 5.6/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-21031?

CVE-2021-21031 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-2021-21031?

Update magento/community-edition to 2.4.1-p1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-21031 is resolved across your whole dependency graph.

How do I detect CVE-2021-21031 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-2021-21031 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2021-21031 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-21031 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-2021-21031?

CVE-2021-21031 has an EPSS (Exploit Prediction Scoring System) score of 1.7%, placing it in the 77th 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-2021-21031?

CVE-2021-21031 is classified as CWE-613 (CWE-613). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-21031 published, and has it been updated?

CVE-2021-21031 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

MEDIUM severity

CVE-2021-21031 — community-edition

MEDIUM

CVE-2021-21031 is a medium-severity (CVSS 5.6) CWE-613 vulnerability in magento/community-edition. A fix is available for magento/community-edition — see the affected versions and patch details below.

Magento Insufficient Session Expiration

Also known asBIT-magento-2021-21031GHSA-4h3p-63x6-vwg2

Published

Feb 11, 2021

Updated

Oct 24, 2026

Affected

3 pkgs

Patched

2 / 3

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.7%probability of exploitation in next 30 days

Lower Risk+0.02%

Lower risk than most CVEs77th percentile — riskier than 77% 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) do not adequately invalidate user sessions. Successful exploitation could lead to unauthorized access to restricted resources. Access to the admin console is not required for successful exploitation.

Affected Packages

3 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘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/community-edition`	all versions	2.3.6`composer require magento/community-edition:^2.3.6`
🐘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 2.4.1-p1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-21031 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-21031 in your dependencies?

Find it across Packagist, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

5.6/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

Low

Raw vector

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

CWE Classification

CWE-613CWE-613

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-2021-21031

GHSA-4h3p-63x6-vwg2

BIT-magento-2021-21031

References

Advisoryhelpx.adobe.com · apsb21 08 Advisorynvd.nist.gov · CVE 2021 21031 Packagegithub.com · magento2

Related vulnerabilities

This CVE is medium severity; 8 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