CVE-2023-23999Network attack vector

Stored script execution via unsanitized style attribute

Published May 18, 2023 · Updated Apr 28, 2026

Stored XSS in MonsterInsights 8.14.0 and earlier allows remote authenticated users to inject scripts through a crafted style attribute. The plugin stores style-attribute input without sufficient sanitization and renders it without adequate output escaping. Contributor-level access is required, and the script runs in the browser of a user who opens the injected page, enabling page-content manipulation and data access in that user's session.

CVSS severity6.5
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stored XSS in MonsterInsights 8.14.0 and earlier allows remote authenticated users to inject scripts through a crafted style attribute. The plugin stores style-attribute input without sufficient sanitization and renders it without adequate output escaping. Contributor-level access is required, and the script runs in the browser of a user who opens the injected page, enabling page-content manipulation and data access in that user's session.

The record

CVE
CVE-2023-23999
Published
May 18, 2023
Updated
Apr 28, 2026
Vendor
MonsterInsights
Product
MonsterInsights
Classifications
CWE-79, CAPEC-592, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 18, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=n/a <=8.14.0 changes=[{"at":"8.14.1","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

MonsterInsights · MonsterInsightsversion=n/a <=8.14.0 changes=[{"at":"8.14.1","status":"unaffected"}]

Published CVSS scores

6.5PatchstackCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
5.4NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/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')
CAPEC-592Stored XSS
T1059.007Command and Scripting Interpreter: JavaScript/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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo