CVE-2023-1400Public exploitNetwork attack vector

Stored XSS via unescaped calendar settings

Published Mar 27, 2023 · Updated Apr 23, 2025

Stored XSS in Webnus Modern Events Calendar Lite before 6.5.2 allows remote authenticated users to inject script through calendar settings. The import/export page stores Google API key and Calendar ID values without sanitizing or escaping them before later output. Administrator-level access is required, and execution requires another user to view the stored markup; multisite remains exposed when unfiltered_html is disabled.

CVSS severity4.8
Medium
EPSS probability0.50%
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 Webnus Modern Events Calendar Lite before 6.5.2 allows remote authenticated users to inject script through calendar settings. The import/export page stores Google API key and Calendar ID values without sanitizing or escaping them before later output. Administrator-level access is required, and execution requires another user to view the stored markup; multisite remains exposed when unfiltered_html is disabled.

The record

CVE
CVE-2023-1400
Published
Mar 27, 2023
Updated
Apr 23, 2025
Vendor
Webnus
Product
Modern Events Calendar Lite
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Mar 27, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Record 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=0 <6.5.2.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Webnus · Modern Events Calendar Liteversion=0 <6.5.2.

Published CVSS scores

4.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
4.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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

Public exploit references

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