CVE-2023-4021
Modern Events Calendar lite < 7.1.0 - Authenticated (Admin+) Stored Cross-Site Scripting
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Modern Events Calendar lite < 7.1.0 - Authenticated (Admin+) Stored Cross-Site Scripting
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.
- Record
CVE-2023-4021- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2023-53914
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.
- Record
EUVD-2023-53914- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-mxc9-v9vg-4xfw
The Modern Events Calendar lite plugin for WordPress is vulnerable to Stored Cross-Site Scripting...
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.
- Record
GHSA-mxc9-v9vg-4xfw- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2023-4021- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N - CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-4021 is a medium vulnerability (CVSS 4.4) in Webnus Modern Events Calendar Lite, published October 20, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.38%, the 31st percentile. No source names a fixed version.