CVE-2026-65048: Ninja Forms Unauthenticated Stored Cross-Site Scripting via Repeatable Fieldset Submission Index

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.5%

EPSS score, percentile 45.2 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

9.3 Critical

CVSS v4.0 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (1)

Which versions are affected?

Affected

• from 3.10.4 to before 3.14.9

Unaffected 3.14.9

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Advisories and patches

• Vendor Changelog (Patch)

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Versions not listed are: affected.

Versions the record lists as unaffected: 3.14.9.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

Ninja Forms plugin for WordPress versions 3.10.4 through 3.14.9 contains an unauthenticated stored cross-site scripting vulnerability in the Repeatable Fieldset feature where parseSubmissionIndex() accepts arbitrary strings as submission indexes without numeric validation, and admin_form_element() interpolates the index directly into HTML without escaping. An unauthenticated attacker can submit a…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-65048 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 21 Jul 2026.
• The CVE record carries a CVSS v4.0 base score of 9.3 (Critical), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.5% (percentile 45.2), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact total.
• The credits in the CVE record name AISLE as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

Ninja Forms Unauthenticated Stored Cross-Site Scripting via Repeatable Fieldset Submission Index

Ninja Forms plugin for WordPress versions 3.10.4 through 3.14.9 contains an unauthenticated stored cross-site scripting vulnerability in the Repeatable Fieldset feature where parseSubmissionIndex() accepts arbitrary strings as submission indexes without numeric validation, and admin_form_element() interpolates the index directly into HTML without escaping. An unauthenticated attacker can submit a public form with a crafted repeater child key containing malicious script payloads, which execute in an administrator's browser when viewing submissions in the WordPress admin panel, enabling session-cookie theft, creation of administrator accounts, installation of malicious plugins, and arbitrary modification of site content.

Source: CVE List, as of 29 Oct 2026. About the data.

Timeline