How severe is CVE-2021-21395?

CVE-2021-21395 has a CVSS score of 4.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-21395?

CVE-2021-21395 affects the following packages: openmage/magento-lts (Packagist), openmage/magento-lts (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2021-21395?

Update openmage/magento-lts to 19.4.22 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-21395 is resolved across your whole dependency graph.

How do I detect CVE-2021-21395 in my Packagist dependencies?

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

How do I mitigate CVE-2021-21395 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2021-21395 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2021-21395, 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-2021-21395?

CVE-2021-21395 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 34th 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-2021-21395?

CVE-2021-21395 is classified as Cross-Site Request Forgery (CSRF) (CWE-352). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-21395 published, and has it been updated?

CVE-2021-21395 was published on January 27, 2023 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-2021-21395 — magento-lts

MEDIUM

CVE-2021-21395 is a medium-severity (CVSS 4.3) Cross-Site Request Forgery (CSRF) vulnerability in openmage/magento-lts. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for openmage/magento-lts — see the affected versions and patch details below.

magento-lts Reset Password not protected against well-timed CSRF

Also known asGHSA-r3c9-9j5q-pwv4

Published

Jan 27, 2023

Updated

Oct 24, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

1 known

Exploitation data as of Nov 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for CVE-2021-21395.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk+0.01%

Lower risk than most CVEs34th percentile — riskier than 34% 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

2 pkgs affected

🐘openmage/magento-lts🐘openmage/magento-lts

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

Magneto LTS (Long Term Support) is a community developed alternative to the Magento CE official releases. Versions prior to 19.4.22 and 20.0.19 are vulnerable to Cross-Site Request Forgery. The password reset form is vulnerable to CSRF between the time the reset password link is clicked and user submits new password. This issue is patched in versions 19.4.22 and 20.0.19. There are no workarounds.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`openmage/magento-lts`	all versions	19.4.22`composer require openmage/magento-lts:^19.4.22`
🐘Packagist	`openmage/magento-lts`	≥ 20.0.0&&< 20.0.19	20.0.19`composer require openmage/magento-lts:^20.0.19`

Affected Products

1 product · 2 configurations

Application

magentoopenmage

≥ 20.0.0 && < 20.0.19

range

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.

Magneto LTS (Long Term Support) is a community developed alternative to …

hackerone.comNVDFeb 2023

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openmage/magento-lts, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update openmage/magento-lts to 19.4.22 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-21395 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-21395 in your dependencies?

Find it across Packagist, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

4.3/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Raw vector

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

CWE Classification

CWE-352Cross-Site Request Forgery (CSRF)

Weaponization

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

OpenSSF Scorecard

Package health score

magento-lts

5.7/10

Code-Review8/10

Maintained10/10

Branch-Protection2/10

Assessed Nov 2, 2026

Timeline

Disclosed

Jan 27, 2023

First exploit

Feb 7, 2023

Last updated

Oct 24, 2026

Identifiers

CVE-2021-21395

GHSA-r3c9-9j5q-pwv4

References

Advisorygithub.com · GHSA r3c9 9j5q pwv4 Advisorypackagist.org · magento lts Advisorynvd.nist.gov · CVE 2021 21395 Webgithub.com · v19.4.22 Webgithub.com · v20.0.19 Packagegithub.com · magento lts Evidencehackerone.com

Related vulnerabilities

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

CVE-2026-42458CVE-2026-42155CVE-2026-42207CVE-2026-40488CVE-2026-40098CVE-2026-25525CVE-2026-25524CVE-2026-25523

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 24, 2026

CVE-2021-21395 — magento-lts

Exploitation Status

Proof-of-concept exploit code exists

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2021-21395 in your dependencies?