---
id: "CVE-2026-120212"
page: "https://infrastack.ai/live/CVE-2026-120212"
kind: "vulnerability"
aliases: ["CVE-2026-120212"]
title: "Web::Simple: single quotes unescaped in HTML::Tags output enables script injection"
severity: "medium"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["html-tags", "package", "perl", "web-simple"]
not_affected_if: ["double-quoted-attributes", "no-user-controlled-values"]
published_at: "2026-11-10T18:17:19+00:00"
first_seen_at: "2026-11-10T18:22:55+00:00"
updated_at: "2026-11-10T18:26:49+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-120212", "first_seen_at": "2026-11-10T18:22:55+00:00"}]
exploit_sources: []
---

# Web::Simple: single quotes unescaped in HTML::Tags output enables script injection

Link for people: https://infrastack.ai/live/CVE-2026-120212 (this .md is for agents)

Web::Simple versions before 0.037 for Perl do not escape single quotes when HTML::Tags builds HTML. A value placed inside a single-quoted attribute can close the attribute and add an event handler, so an attacker can run script in the victim's browser.

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

## How to check

- Check the installed Web::Simple version with `perl -MWeb::Simple -e 'print $Web::Simple::VERSION'`
- Search application code for HTML::Tags or XML::Tags output that interpolates user values into single-quoted attributes, such as `href='$value'`

## Fix

- Web::Simple: move to `0.037` or later

## Timeline

- 2026-11-10T18:22:55+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-120212

## Documents

- [fix] Patch: github.com https://github.com/p5sagit/Web-Simple/commit/de0b7743f7015ec2c1c678dfdaa4bc6f5ccfb640.patch

## From the sources

Web::Simple versions before 0.037 for Perl do not escape single quotes in HTML::Tags output.

HTML::Tags and XML::Tags escape a plain string value by replacing only &, ", < and > with entities. A value interpolated into a single-quoted attribute, as in <a href='$value'>, can therefore close the attribute and add new ones, such as an event handler. Double-quoted attributes are not affected.

An attacker who controls a value that an application interpolates into a single-quoted attribute can inject script into the generated page.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_