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.
CVSS v4.0 Metrics
Exploitability
Attack VectorNetwork
ComplexityLow
RequirementsPresent
PrivilegesLow
User InteractionActive
Threat
Exploit MaturityPoC
Vulnerable System
ConfidentialityHigh
IntegrityLow
AvailabilityNone
Subsequent System
ConfidentialityNone
IntegrityNone
AvailabilityNone
Supplemental
SafetyNegligible
AutomatableYes
RecoveryAutomatic
Value DensityConcentrated
UrgencyMedium
Change Log
| Date | Source | Changes | Score |
|---|
| 2026-07-21 | PoC | E: U→P | 1.9 → 4.8 |
| 2026-07-21 | cve.org | initial, patch: Unavailable | 1.9 |
Affected Software
| Vendor | Product | Version |
|---|
| wordpress | wordpress | 5.8 |
| WordPress | wordpress-develop | 5.8 beta 1 |
| WordPress | wordpress-develop | 5.8 beta 2 |
Published: 2021-09-09
