CVE-2021-24789: Flat Preloader < 1.5.5 - Admin+ Stored Cross-Site Scripting

Severity: medium (CVSS 4.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-11-01 · updated 2026-06-17
Weakness: CWE-79

Description

The Flat Preloader WordPress plugin before 1.5.5 does not escape some of its settings when outputting them in attribute in the frontend, which could allow high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html is disallowed

Affected products

Flat Preloader: before 1.5.5 — fixed in 1.5.5

How to fix

Upgrade to a fixed version: Flat Preloader 1.5.5. Check the vendor advisory for mitigations.

References

https://wpscan.com/vulnerability/e8550ccd-3898-4e27-aca9-ade89823ff4d
https://wpscan.com/vulnerability/e8550ccd-3898-4e27-aca9-ade89823ff4d

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