VulnerabilityModified

CVE-2021-39341

HIGH 8.2EPSS 21.9%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 21.9%, higher than 98% of all known CVEs. Patch or mitigate before the next change window.

Description

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.

CVSS 3.1: 8.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
EPSS: 21.93% probability · 98th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-285, CWE-319, CWE-863
Affected: optinmonster/optinmonster
Source: security@wordfence.com

EPSS trend

EPSS 21.9% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

https://plugins.trac.wordpress.org/browser/optinmonster/trunk/OMAPI/RestApi.php?rev=2606519#L1460Third Party Advisory
https://wordfence.com/vulnerability-advisories/#CVE-2021-39341Third Party Advisory
https://www.wordfence.com/blog/2021/10/1000000-sites-affected-by-optinmonster-vulnerabilities/Exploit, Third Party Advisory
https://plugins.trac.wordpress.org/browser/optinmonster/trunk/OMAPI/RestApi.php?rev=2606519#L1460Third Party Advisory
https://wordfence.com/vulnerability-advisories/#CVE-2021-39341Third Party Advisory
https://www.wordfence.com/blog/2021/10/1000000-sites-affected-by-optinmonster-vulnerabilities/Exploit, Third Party Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.