What is CVE-2023-40000?

CVE-2023-40000 is a high-severity vulnerability in Litespeedtech Litespeed Cache, classified under Cross-site Scripting. CVSS score: 8.3/10. Published 2024-04-16.

How severe is CVE-2023-40000?

High severity. CVSS v3 base score is 8.3 out of 10.

Is CVE-2023-40000 known to be exploited?

9 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Litespeedtech Litespeed Cache

CVE-2023-40000

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2024-04-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.549 (99.0th percentile), scored 2026-10-18.

High probability of exploitation in the next 30 days — patch promptly. 99th percentile — 99.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.549 · newest: 0.549 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

References

patchstack.com/database/vulnerability/litespeed-cache/wordpress-litespeed-cache… (Third Party Advisory, vdb-entry)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (Exploit)

Frequently asked questions

What is CVE-2023-40000?: CVE-2023-40000 is a high-severity vulnerability in Litespeedtech Litespeed Cache, classified under Cross-site Scripting. CVSS score: 8.3/10. Published 2024-04-16.
How severe is CVE-2023-40000?: High severity. CVSS v3 base score is 8.3 out of 10.
Is CVE-2023-40000 known to be exploited?: 9 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.