What is CVE-2021-36821?

CVE-2021-36821 is a high-severity vulnerability in Incsub Forminator, classified under Cross-site Scripting. CVSS score: 7.1/10. Published 2023-03-16.

How severe is CVE-2021-36821?

High severity. CVSS v3 base score is 7.1 out of 10.

Is CVE-2021-36821 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Incsub Forminator

CVE-2021-36821

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in WPMU DEV Forminator allows Stored XSS.This issue affects Forminator: from n/a through 1.14.11.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2023-03-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.004 (32.3th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 32.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

20142995/nuclei-templates

References

patchstack.com/database/vulnerability/forminator/wordpress-forminator-plugin-1-… (Third Party Advisory, vdb-entry)

Frequently asked questions

What is CVE-2021-36821?: CVE-2021-36821 is a high-severity vulnerability in Incsub Forminator, classified under Cross-site Scripting. CVSS score: 7.1/10. Published 2023-03-16.
How severe is CVE-2021-36821?: High severity. CVSS v3 base score is 7.1 out of 10.
Is CVE-2021-36821 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.