OptinMonster <= 2.6.4 Unprotected REST-API Endpoints
Priority MEDIUM 61CWE-285Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass, Information disclosure
- Confidentiality · integrity · availability
- High · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-285 and CWE-319.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.21929 97th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- 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 |
|---|---|---|---|---|---|
| OptinMonster | OptinMonster | 2.6.4 – 2.6.4 | — | No fix listed | CNA |
- OptinMonster VendorOptinMonster Affected 2.6.4 – 2.6.4 Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:optinmonster:optinmonster:*:*:*:*:*:wordpress:*:* | up to 2.6.4 | Vulnerable | OptinMonster |
- cpe:2.3:a:optinmonster:optinmonster:*:*:*:*:*:wordpress:*:* Versions up to 2.6.4 Vulnerable ·OptinMonster
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-39341
- 2026-10-03 Alias added: GHSA-whcc-jgf3-q7pm
References
More Optinmonster vulnerabilities
- TI-2023-00732 Popup Builder by OptinMonster < 2.12.2 - Subscriber+ Arbitrary Post Content Disclosure CVSS 3.1MEDIUM 6.5
- TI-2021-16695 OptinMonster <= 2.6.0 Reflected Cross-Site Scripting CVSS 3.1MEDIUM 6.1
- TI-2024-03774 Cross-site scripting in smub Popup Builder & Popup Maker for WordPress – OptinMonster… CVSS 3.1MEDIUM 6.4
- TI-2016-09034 The optinmonster plugin before 1.1.4.6 for WordPress has incorrect access control for… CVSS 3.1MEDIUM 5.3
Sources
- CVE-2021-39341 · CVE Program
- CVE-2021-39341 · NVD
- FIRST EPSS
- GHSA-whcc-jgf3-q7pm · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences