CVE-2023-40000: WordPress LiteSpeed Cache plugin <= 5.7 - Unauthenticated Site Wide Stored XSS vulnerability

Is it exploited?

Reported, not confirmed by CISA. VulnCheck KEV lists it as exploited in the wild. CISA has not added it to its Known Exploited Vulnerabilities catalog as of 29 Oct 2026.

VulnCheck KEV lists it since 3 May 2024. It cites 3 public reports, the first from 3 May 2024.

• wpscan.com
• fastly.com
• app.crowdsec.net

How likely is exploitation in the next 30 days?

54.9%

EPSS score, percentile 99 of all scored records. A probability estimated by FIRST, not a report of exploitation.

CISA's SSVC assessment in the CVE record lists exploitation as poc.

How severe?

8.3 High

CVSS v3.1 base score, given by the CNA

What should I do?

Update to 5.7.0.1 or a higher version.Solution from the CVE record.

CISA has set no required action, because the vulnerability is not in KEV.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

• 5.7 and earlier

Unaffected from 5.7.0.1

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; VulnCheck KEV, as of 30 Oct 2026; FIRST EPSS, as of 30 Oct 2026; CVE List, as of 30 Oct 2026. About the data.

Description

WordPress LiteSpeed Cache plugin <= 5.7 - Unauthenticated Site Wide Stored XSS vulnerability

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in LiteSpeed Technologies LiteSpeed Cache allows Stored XSS.This issue affects LiteSpeed Cache: from n/a through 5.7.

Source: CVE List, as of 30 Oct 2026. About the data.

What to do

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

This summary is based on the CVE record as of 30 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

Source: CVE List, as of 30 Oct 2026. About the data.

Timeline