CVE-2026-19872

[CVE catalog]

Severity

Medium · CVSS 6.1CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Published

Sep 8, 2026, 8:08:21 PM UTC

Updated

Sep 8, 2026, 8:17:29 PM UTC

Source

[NVD] · [CVE record]

EPSS

0.33% · Oct 25, 2026

HTML::FormHandler versions before 0.410000 for Perl allow cross-site scripting via a submitted value rendered unescaped in an error message. The wrappers and renderers that emit a form's errors interpolate the error string straight into HTML with no escaping. Two of the library's own messages, no_match and not_allowed, splice the submitted value into that string, and a failing type constraint puts the rejected value into the message it builds, which _apply_actions hands to add_error. A field declared with a check regexp, a check list or a type constraint reaches those messages, with no custom validator and no non-default configuration. Errors rendered through an application's own escaping template layer rather than the library's rendering roles are not affected. A request over the network that submits markup to such a field gets it back live inside the error span, running script in the victim's origin. Re-rendering a rejected value later gives the stored variant.