TI-2023-03733 Aliases CVE-2023-4021 GHSA-mxc9-v9vg-4xfw

Modern Events Calendar lite < 7.1.0 - Authenticated (Admin+) Stored Cross-Site Scripting

LOW 22CWE-79Published 2023-10-20 · Updated 2026-04-08

Key facts

Attack vector: Network
Privileges required: High
User interaction: Required
Attack complexity: Low
Impact type: Cross-site scripting
Confidentiality · integrity · availability: Low · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-79.

Summary

The Modern Events Calendar lite plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Google API key and Calendar ID in versions up to, but not including, 7.1.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00378 31st percentileScored 2026-11-07

Fix Fixed Modern Events Calendar Lite (webnus/): 7.1.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Webnus	Modern Events Calendar Lite	before 7.1.0	7.1.0	Patch available	CNA

Modern Events Calendar Lite VendorWebnus Affected before 7.1.0 Fixed in 7.1.0 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:webnus:modern_events_calendar_lite::::::wordpress::*	before 7.1.0	Vulnerable	Webnus

cpe:2.3:a:webnus:modern_events_calendar_lite:*:*:*:*:*:wordpress:*:* Versions before 7.1.0 Vulnerable ·Webnus

Remediation

Fix · CNA Modern Events Calendar Lite (webnus/) Fixed in 7.1.0

Timeline

2026-10-02 Threatist record created from CVE-2023-4021
2026-10-03 Alias added: GHSA-mxc9-v9vg-4xfw

References

Patch 1

https://webnus.net/modern-events-calendar/change-log/

Advisory 1

https://www.wordfence.com/threat-intel/vulnerabilities/id/f213fb42-5bab-4017-80ea-ce6543031af2?source=cve

TI-2021-07225 Modern Events Calendar < 6.1.5 - Unauthenticated Blind SQL Injection CVSS 3.1CRITICAL 9.8
TI-2021-06437 Modern Events Calendar Lite < 5.16.5 - Authenticated Arbitrary File Upload leading to RCE CVSS 3.1HIGH 7.2
TI-2022-00289 Modern Events Calendar Lite < 6.4.0 - Contributor+ Stored Cross Site Scripting CVSS 3.1MEDIUM 5.4
TI-2021-06438 Modern Events Calendar Lite < 5.16.5 - Unauthenticated Events Export CVSS 3.1HIGH 7.5
TI-2023-01324 Modern Events Calendar lite < 6.5.2 - Admin+ Stored XSS CVSS 3.1MEDIUM 4.8
TI-2024-05057 Modern Events Calendar <= 7.11.0 - Authenticated (Subscriber+) Arbitrary File Upload CVSS 3.1HIGH 8.8

See all 17 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences