Gravity Forms Stored XSS via Insufficient Input Sanitization

The Gravity Forms plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Post Body Field Value in all versions up to, and including, 2.10.5 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The exploit survives save-time sanitization because wp_kses_post allows the required HTML tags and attributes, and the client-side tooltip script re-parses the browser-decoded aria-label value as innerHTML while only stripping script elements, leaving onerror and other event-handler attributes fully intact and executable.

Casky was already ahead

This CVE exploits attack patterns that Casky's 323matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

Gravity Forms, one of WordPress's most popular form-building plugins, contains a stored cross-site scripting (XSS) vulnerability affecting all versions up to 2.10.5. The flaw exists in the Post Body Field Value functionality, where insufficient input sanitization and output escaping allows unauthenticated attackers to inject arbitrary JavaScript that persists in the database. The vulnerability is particularly dangerous because wp_kses_post—WordPress's standard sanitization function—intentionally permits certain HTML tags and attributes for legitimate content, making it ineffective against this specific attack vector. Any user visiting a page containing an injected form field will execute the attacker's malicious script, making this a wide-impact threat affecting website visitors, not just administrators.

Casky.ai's 323 mapped skills detect the attack patterns underlying this vulnerability by analyzing Initial Access (TA0001) and Persistence (TA0043) techniques. Practitioners using Casky will observe detection patterns for client-side payload delivery and post-exploitation behavior: reconnaissance of form field structure, injection of malicious script tags within form values, and validation that payloads survive the sanitization routine. The platform's Claude AI-powered analysis identifies the specific gap between sanitization timing and rendering—where wp_kses_post allows dangerous attributes during save operations. Security teams can map observed form manipulation attempts, unexpected JavaScript execution in form submissions, and stored XSS payloads in database queries to this CVE, enabling rapid triage and prioritization of Gravity Forms instances requiring immediate patching to version 2.10.6 or later.

Live Threat IntelligenceComing soon

Casky Risk Score

—

EPSS Probability

—

Shodan Exposure

—

GreyNoise Signal

—

Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

323 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-16649.

Abuse of Public-Facing API: Mobile API Abuse

mobile security · low

Run

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

MITRE ATT&CK Techniques

TA0001 TA0043

Investigate the attack patterns behind CVE-2026-16649

Casky has 323 skills that investigate the attack patterns behind CVE-2026-16649. Run one and get CVSS-scored findings in 3 minutes.

Run the skill that detects this →

X Instagram LinkedIn