CVE-2021-39341
OptinMonster <= 2.6.4 Unprotected REST-API Endpoints
The OptinMonster WordPress plugin is vulnerable to sensitive information disclosure and unauthorized setting updates due to insufficient authorization validation via the logged_in_or_has_api_key function in the ~/OMAPI/RestApi.php file that can used to exploit inject malicious web scripts on sites with the plugin installed. This affects versions up to, and including, 2.6.4.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
OptinMonster <= 2.6.4 Unprotected REST-API Endpoints
The OptinMonster WordPress plugin is vulnerable to sensitive information disclosure and unauthorized setting updates due to insufficient authorization validation via the logged_in_or_has_api_key function in the ~/OMAPI/RestApi.php file that can used to exploit inject malicious web scripts on sites with the plugin installed. This affects versions up to, and including, 2.6.4.
- Record
CVE-2021-39341- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-285, CWE-319
- Updated
- 2026-11-02
EUVDEUVD-2021-25702
The OptinMonster WordPress plugin is vulnerable to sensitive information disclosure and unauthorized setting updates due to insufficient authorization validation via the logged_in_or_has_api_key function in the ~/OMAPI/RestApi.php file that can used to exploit inject malicious web scripts on sites with the plugin installed. This affects versions up to, and including, 2.6.4.
- Record
EUVD-2021-25702- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-whcc-jgf3-q7pm
The OptinMonster WordPress plugin is vulnerable to sensitive information disclosure and...
The OptinMonster WordPress plugin is vulnerable to sensitive information disclosure and unauthorized setting updates due to insufficient authorization validation via the logged_in_or_has_api_key function in the ~/OMAPI/RestApi.php file that can used to exploit inject malicious web scripts on sites with the plugin installed. This affects versions up to, and including, 2.6.4.
- Record
GHSA-whcc-jgf3-q7pm- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-285, CWE-863
- Updated
- 2026-11-02
NVD
The OptinMonster WordPress plugin is vulnerable to sensitive information disclosure and unauthorized setting updates due to insufficient authorization validation via the logged_in_or_has_api_key function in the ~/OMAPI/RestApi.php file that can used to exploit inject malicious web scripts on sites with the plugin installed. This affects versions up to, and including, 2.6.4.
- Record
CVE-2021-39341- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N - CVSS 2.0
- 6.4 Medium
AV:N/AC:L/Au:N/C:P/I:P/A:N - Weakness
- CWE-285, CWE-319, CWE-863
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Nuclei | OptinMonster Plugin < 2.6.5 - Unprotected REST-API |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, Nuclei, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-39341 is a high vulnerability (CVSS 8.2) in Optinmonster, published November 1, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 21.9%, the 97th percentile. No source names a fixed version.