CVE-2023-4372Network attack vector

Stored XSS via unescaped ESI cache attribute

Published Jan 11, 2024 · Updated Apr 8, 2026

Stored XSS in LiteSpeed Cache for WordPress 5.6 and earlier allows remote authenticated users to inject scripts through the ESI shortcode. The ESI class shortcode method accepts the user-controlled cache attribute and passes it to sub_esi_block, which inserts the derived control value into an esi:include element without attribute escaping. Contributor-level access and the non-default ESI setting are required; a submitted payload executes in the browser whenever the affected page is requested.

CVSS severity6.4
Medium
EPSS probability16.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in LiteSpeed Cache for WordPress 5.6 and earlier allows remote authenticated users to inject scripts through the ESI shortcode. The ESI class shortcode method accepts the user-controlled cache attribute and passes it to sub_esi_block, which inserts the derived control value into an esi:include element without attribute escaping. Contributor-level access and the non-default ESI setting are required; a submitted payload executes in the browser whenever the affected page is requested.

The record

CVE
CVE-2023-4372
Published
Jan 11, 2024
Updated
Apr 8, 2026
Vendor
LiteSpeed Technologies
Product
LiteSpeed Cache for WordPress
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 11, 2024CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=5.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

LiteSpeed Technologies · LiteSpeed Cache for WordPressversion=0 <=5.6

Published CVSS scores

6.4Wordfence CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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