---
id: "CVE-2026-121632"
kind: "vulnerability"
aliases: ["CVE-2026-121632"]
title: "Data::MuForm for Perl: form options rendered into HTML without escaping"
severity: "medium"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["data-muform", "package", "perl", "web-forms"]
not_affected_if: ["not-using-data-muform", "static-option-literals"]
published_at: "2026-11-04T15:17:42+00:00"
first_seen_at: "2026-11-04T15:27:30+00:00"
updated_at: "2026-11-04T15:28:34+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121632", "first_seen_at": "2026-11-04T15:27:30+00:00"}]
---

# Data::MuForm for Perl: form options rendered into HTML without escaping

Data::MuForm versions through 0.05 write option values, labels and attribute values into rendered HTML without escaping them. An attacker who controls option text built from data can inject JavaScript that runs in a victim's browser when the page is viewed.

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

## How to check

- Check whether the project depends on `Data::MuForm` and at what version, for example with `cpanm --info Data::MuForm` or the Perl dependency list.
- Look for forms that build select, radio or checkbox options from database rows, `options_<field_name>` methods, `build_options` methods, or `element_attr` values that include user-supplied text.

## Timeline

- 2026-11-04T15:27:30+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121632

## From the sources

Data::MuForm versions through 0.05 for Perl render attribute values and option labels into HTML without escaping.

process_attrs writes each attribute value into the markup as is. The select, radio group and checkbox group renderers pass each option to it, so an option's value becomes an unescaped attribute. Option and option group labels are also unescaped, the group label inside a label attribute and the others in element content.

Any application whose option list is built from data rather than literals, using an options_<field_name> method, a build_options method or a DBIC model, allows attacker-influenced text in an option value or label that can embed JavaScript in rendered pages. Attribute values built from data, such as through element_attr, are affected the same way.

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