CVE-2021-40940

Name: CVE-2021-40940
Creator: NVD / NIST
Published: 2022-06-15T17:15:08.573+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.58%

Last modified Jun 17, 2026

CVE-2021-40940 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Monstra 3.0.4 does not filter the case of php, which leads to an unrestricted file upload vulnerability.. EPSS estimates a 1.58% chance of exploitation in the next 30 days.

Description

Monstra 3.0.4 does not filter the case of php, which leads to an unrestricted file upload vulnerability.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

1.58%

72.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-434

Affected Software

Vendor	Product	Versions
Monstra	Monstra	<= 3.0.4

References

https://github.com/monstra-cms/monstra/issues/471Exploit, Issue Tracking, Patch, Third Party Advisory
https://github.com/monstra-cms/monstra/issues/471Exploit, Issue Tracking, Patch, Third Party Advisory

Timeline

Published: Jun 15, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-40940?

Monstra 3.0.4 does not filter the case of php, which leads to an unrestricted file upload vulnerability.

How severe is CVE-2021-40940?

CVE-2021-40940 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.58% probability of exploitation in the next 30 days.

How do I fix CVE-2021-40940?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-40940?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST