Cross-site scripting in Form Plugin - #VU165519
Published: November 11, 2026
Vulnerability identifier: #VU165519
CSH Severity: Medium
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: N/A
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary JavaScript in the context of an affected web page.
The vulnerability exists due to improper neutralization of user-controlled markup in the target response handling in src/jquery.form.js when the target option is configured without dataType and an application/json response is parsed into an array or object and passed to .html(). A remote attacker can supply a string containing a payload such as <img src=x onerror=alert(1)> through the JSON endpoint to execute arbitrary JavaScript when the response is inserted into the page.
The iframe transport is not affected because its response data remains a string.
Affected software
Form Plugin
Remediation
Install security update from vendor's website.
Form Plugin - update to 4.4.0