CVE-2021-39320 json
underConstruction <= 1.18 - Reflected Cross-Site Scripting
published 2021-09-01 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-25681
- cvss
- 6.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.3%
- EPSS 2.3% chance of exploitation in 30 days, percentile 83%
- public exploits
- 0
- none known, plus a Nuclei check
Summary
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.
Patch / fix
- underconstruction_project underconstruction 1.19
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 18 mo ago
Exploit prediction
2.32% chance of exploitation in the next 30 days, higher than 83% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- Nuclei template WordPress Under Construction <1.19 - Cross-Site Scripting nuclei detection template
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 4.3 | AV:N/AC:M/Au:N/C:N/I:P/A:N |
Affected products
- Noah Kagan underConstruction
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
- Technology feeds
References
-
wpscan.com
/vulnerability/49ae1df0-d6d2-4cbb-9a9d-bf3599429875
third-party-advisory
-
wordfence.com
/vulnerability-advisories/#CVE-2021-39320
third-party-advisory
Sources
- CVE List CVE-2021-39320
- NVD CVE-2021-39320
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.