XSS in WordPress
CVE-2021-39202
WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. In affected versions the widgets editor introduced in WordPress 5.8 beta 1 has improper handling of HTML input in the Custom HTML feature. This leads to stored XSS in the custom HTML widget. This has been patched in WordPress 5.8. It was only present during the testing/beta phase of WordPress 5.8.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N.
EPSS exploit prediction
EPSS: 0.008 (55.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 55.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000
Affected products
- WordPress — versions 5.8
- WordPress Wordpress-Develop — versions 5.8 beta 1, 5.8 beta 2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/WordPress/wordpress-develop/security/advisories/GHSA-fr6h-3855-j297 (Third Party Advisory)
- hackerone.com/reports/1222797 (Permissions Required)
Frequently asked questions
- What is CVE-2021-39202?
- CVE-2021-39202 is a high-severity vulnerability in WordPress, classified under Cross-site Scripting. CVSS score: 7.6/10. Published 2021-09-09.
- How severe is CVE-2021-39202?
- High severity. CVSS v3 base score is 7.6 out of 10.
- Is CVE-2021-39202 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.