CVE-2021-39320
underConstruction <= 1.18 - Reflected Cross-Site Scripting
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
underConstruction <= 1.18 - Reflected Cross-Site Scripting
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.
- Record
CVE-2021-39320- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2021-25681
The underConstruction plugin <= 1.18 for WordPress echoes out the raw value of $GLOBALS['PHP_SELF'] in the ucOptions.php file. On certain configurations including Apache+modPHP, this makes it possible to use it to perform a reflected Cross-Site Scripting attack by injecting malicious code in the request path.
- Record
EUVD-2021-25681- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-p83h-qp2w-3vv5 No score
The underConstruction plugin <= 1.18 for WordPress echoes out the raw value of `$GLOBALS[...
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.
- Record
GHSA-p83h-qp2w-3vv5- Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2021-39320- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Nuclei | WordPress Under Construction <1.19 - Cross-Site Scripting |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, Nuclei, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-39320 is a medium vulnerability (CVSS 6.1) in Noah Kagan Underconstruction, published September 1, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.32%, the 83rd percentile. No source names a fixed version.