CVE-2026-82867

@pdfme/schemas before 5.5.9 contains a cross-site scripting vulnerability in the Select schema plugin that fails to sanitize option values before interpolating them into HTML via innerHTML. Attackers can supply malicious templates with crafted option values containing HTML and JavaScript to execute arbitrary code in users' browsers.

@pdfme/schemas before 5.5.9 contains a cross-site scripting vulnerability in the Select schema plugin that fails to sanitize option values before interpolating them into HTML via innerHTML. Attackers can supply malicious templates with crafted option values containing HTML and JavaScript to execute arbitrary code in users' browsers.

@pdfme/schemas before 5.5.9 contains a cross-site scripting vulnerability in the Select schema plugin that fails to sanitize option values before interpolating them into HTML via innerHTML. Attackers can supply malicious templates with crafted option values containing HTML and JavaScript to execute arbitrary code in users' browsers.

Summary

The Select schema plugin in @pdfme/schemas constructs HTML from template-defined option values using unsanitized string interpolation and sets it via innerHTML, enabling arbitrary JavaScript execution.

Details

In packages/schemas/src/select/index.ts, lines 159-164, the Select schema's ui renderer builds <option> elements by directly interpolating option values from the template into an HTML string:

const options = Array.isArray(schema.options) ? schema.options : [];
selectElement.innerHTML = options
  .map(
    (option) =>
      `<option value="${option}" ${option === value ? 'selected' : ''}>${option}</option>`,
  )
  .join('');

The option values come from schema.options, which is an array of strings defined in the template JSON. These values are interpolated directly into the HTML string without any escaping of <, >, ", &, or other HTML-special characters. An option value containing "> breaks out of the value attribute and allows injection of arbitrary HTML elements and event handlers.

Proof of Concept

Loading the following template into a pdfme Form or Designer component triggers JavaScript execution:

{
  "basePdf": { "width": 210, "height": 297, "padding": [20, 20, 20, 20] },
  "schemas": [[
    {
      "name": "malicious_select",
      "type": "select",
      "content": "Normal",
      "options": [
        "Normal",
        "\"></option><img src=x onerror=\"alert(document.domain)\">"
      ],
      "position": { "x": 20, "y": 20 },
      "width": 80,
      "height": 10
    }
  ]]
}

The injected <img onerror> element executes JavaScript because it is parsed as HTML when assigned to selectElement.innerHTML.

Attack Vectors

The options array is defined in the template (not by form-filling end users). The attack requires a malicious template to be loaded, which can happen via:

1. File upload (e.g., "Load Template" functionality in applications)
2. Shared/imported templates in multi-tenant applications
3. Templates stored in databases without content sanitization
4. The updateTemplate() API being called with untrusted data

This vulnerability is triggered in Form mode (for non-readOnly select fields) and Designer mode when the select element is rendered.

Impact

An attacker who can supply a malicious template can execute arbitrary JavaScript in the browser of any user who views or interacts with the template. This enables:

• Session hijacking via cookie/token theft
• Keylogging of form input data
• Phishing and page modification
• Data exfiltration

Suggested Fix

Use DOM APIs to create option elements safely instead of string interpolation:

options.forEach((option) => {
  const optionEl = document.createElement('option');
  optionEl.value = option;
  optionEl.textContent = option;
  if (option === value) optionEl.selected = true;
  selectElement.appendChild(optionEl);
});

Alternatively, HTML-encode option values before interpolation:

const escape = (s) => s.replace(/&/g, '&amp;').replace(/"/g, '&quot;').replace(/</g, '&lt;').replace(/>/g, '&gt;');

@pdfme/schemas before 5.5.9 contains a cross-site scripting vulnerability in the Select schema plugin that fails to sanitize option values before interpolating them into HTML via innerHTML. Attackers can supply malicious templates with crafted option values containing HTML and JavaScript to execute arbitrary code in users' browsers.

@pdfme/schemas before 5.5.9 contains a cross-site scripting vulnerability in the Select schema plugin that fails to sanitize option values before interpolating them into HTML via innerHTML. Attackers can supply malicious templates with crafted option values containing HTML and JavaScript to execute arbitrary code in users' browsers.

Summary

The Select schema plugin in @pdfme/schemas constructs HTML from template-defined option values using unsanitized string interpolation and sets it via innerHTML, enabling arbitrary JavaScript execution.

Details

In packages/schemas/src/select/index.ts, lines 159-164, the Select schema's ui renderer builds <option> elements by directly interpolating option values from the template into an HTML string:

const options = Array.isArray(schema.options) ? schema.options : [];
selectElement.innerHTML = options
  .map(
    (option) =>
      `<option value="${option}" ${option === value ? 'selected' : ''}>${option}</option>`,
  )
  .join('');

The option values come from schema.options, which is an array of strings defined in the template JSON. These values are interpolated directly into the HTML string without any escaping of <, >, ", &, or other HTML-special characters. An option value containing "> breaks out of the value attribute and allows injection of arbitrary HTML elements and event handlers.

Proof of Concept

Loading the following template into a pdfme Form or Designer component triggers JavaScript execution:

{
  "basePdf": { "width": 210, "height": 297, "padding": [20, 20, 20, 20] },
  "schemas": [[
    {
      "name": "malicious_select",
      "type": "select",
      "content": "Normal",
      "options": [
        "Normal",
        "\"></option><img src=x onerror=\"alert(document.domain)\">"
      ],
      "position": { "x": 20, "y": 20 },
      "width": 80,
      "height": 10
    }
  ]]
}

The injected <img onerror> element executes JavaScript because it is parsed as HTML when assigned to selectElement.innerHTML.

Attack Vectors

The options array is defined in the template (not by form-filling end users). The attack requires a malicious template to be loaded, which can happen via:

1. File upload (e.g., "Load Template" functionality in applications)
2. Shared/imported templates in multi-tenant applications
3. Templates stored in databases without content sanitization
4. The updateTemplate() API being called with untrusted data

This vulnerability is triggered in Form mode (for non-readOnly select fields) and Designer mode when the select element is rendered.

Impact

An attacker who can supply a malicious template can execute arbitrary JavaScript in the browser of any user who views or interacts with the template. This enables:

• Session hijacking via cookie/token theft
• Keylogging of form input data
• Phishing and page modification
• Data exfiltration

Suggested Fix

Use DOM APIs to create option elements safely instead of string interpolation:

options.forEach((option) => {
  const optionEl = document.createElement('option');
  optionEl.value = option;
  optionEl.textContent = option;
  if (option === value) optionEl.selected = true;
  selectElement.appendChild(optionEl);
});

Alternatively, HTML-encode option values before interpolation:

const escape = (s) => s.replace(/&/g, '&amp;').replace(/"/g, '&quot;').replace(/</g, '&lt;').replace(/>/g, '&gt;');