CVE-2021-39320

Name: CVE-2021-39320
Creator: NVD / NIST
Published: 2021-09-01T15:15:12.653+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 2.33%

Last modified Jun 17, 2026

CVE-2021-39320 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. The underConstruction plugin <= 1.18 for WordPress echoes out the raw value of `$GLOBALS['PHP_SELF']` in the ucOptions.php file. On certain configurations including Apache+modPHP, this makes it possible to use it to perform a reflected Cross-Site Scripting attack by injecting malicious code in the request path.. EPSS estimates a 2.33% chance of exploitation in the next 30 days.

Description

The underConstruction plugin <= 1.18 for WordPress echoes out the raw value of `$GLOBALS['PHP_SELF']` in the ucOptions.php file. On certain configurations including Apache+modPHP, this makes it possible to use it to perform a reflected Cross-Site Scripting attack by injecting malicious code in the request path.

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

2.33%

81.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Underconstruction Project	Underconstruction	< 1.19

References

https://wpscan.com/vulnerability/49ae1df0-d6d2-4cbb-9a9d-bf3599429875Third Party Advisory
https://www.wordfence.com/vulnerability-advisories/#CVE-2021-39320Third Party Advisory
https://wpscan.com/vulnerability/49ae1df0-d6d2-4cbb-9a9d-bf3599429875Third Party Advisory
https://www.wordfence.com/vulnerability-advisories/#CVE-2021-39320Third Party Advisory

Timeline

Published: Sep 1, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-39320?

How severe is CVE-2021-39320?

CVE-2021-39320 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 2.33% probability of exploitation in the next 30 days.

How do I fix CVE-2021-39320?

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-2021-39320?

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

Scan your code now

Source: NVD / NIST