---
id: "CVE-2026-78190"
kind: "vulnerability"
aliases: ["CVE-2026-78190"]
title: "WebDyne Perl: request parameters reflected unescaped into form fields enable XSS"
severity: "medium"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["package", "perl", "web-apps", "webdyne"]
not_affected_if: ["no-request-params-in-form-tags", "static-content-only"]
published_at: "2026-10-31T15:16:54+00:00"
first_seen_at: "2026-10-31T15:36:19+00:00"
updated_at: "2026-10-31T15:36:40+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-78190", "first_seen_at": "2026-10-31T15:36:19+00:00"}]
---

# WebDyne Perl: request parameters reflected unescaped into form fields enable XSS

WebDyne, a Perl web framework, copies request parameters unescaped into form field value attributes in its textfield, password_field and filefield tags. An attacker can use a crafted link to inject script that runs in the victim's browser on affected pages.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed WebDyne version with `perl -MWebDyne -e 'print $WebDyne::VERSION'` or the module's version in your cpanfile or lockfile; versions from 2.014 before 3.022 are affected.
- Search your templates for `textfield`, `password_field` or `filefield` tags that take request parameters.
- Check whether `WEBDYNE_CGI_AUTOESCAPE` is set in your configuration; the default is off and enabling it does not help from 2.022 on.

## Fix

- WebDyne: move to `3.022` or later (the sources state the fixed version is 3.022).

## Timeline

- 2026-10-31T15:36:19+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-78190

## From the sources

WebDyne versions from 2.014 before 3.022 for Perl reflect request parameters unescaped into form field values, allowing cross-site scripting.

The textfield, password_field and filefield tags fill their value attribute from the request parameter of the same name. WEBDYNE_CGI_AUTOESCAPE, which controls escaping of these values, defaults to off. From 2.022, WebDyne::HTML::Tiny also replaced its entity_encode method with one that returns its input unchanged, so enabling WEBDYNE_CGI_AUTOESCAPE has no effect.

A remote attacker can inject script into any page using these tags through a crafted link.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_