Unstructured-IO Unstructured up to 0.24.0 HTML Generation ontology.py to_html HTML injection

Summaryinfo

A vulnerability classified as problematic has been found in Unstructured-IO Unstructured up to 0.24.0. Affected is the function to_html of the file unstructured/documents/ontology.py of the component HTML Generation. Performing a manipulation results in HTML injection. This vulnerability is identified as CVE-2026-104250. The attack can be initiated remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Unstructured-IO Unstructured up to 0.24.0. This affects the function to_html of the file unstructured/documents/ontology.py of the component HTML Generation. The manipulation with an unknown input leads to a html injection vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. The summary by CVE is:

The unstructured library provides open-source components for ingesting and pre-processing images and text documents, such as PDFs, HTML, Word docs, and many more. Prior to 0.24.1, partition_html(html_parser_version="v2") and the VLM partitioner can preserve untrusted document tags, attributes, text, and link targets in metadata.text_as_html, while elements_to_html() emits the result as an HTML document. The to_html() path in unstructured/documents/ontology.py does not escape output or reject unsafe URL schemes, allowing event-handler attributes, attribute breakout markup, and javascript: links to survive parsing. When the generated HTML or text_as_html is rendered in a browser, attacker-controlled script can execute in the viewer's origin, including in document-ingestion workflows where a privileged reviewer opens submitted content. This issue is fixed in version 0.24.1.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-104250 since 10/01/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

Upgrading to version 0.24.1 eliminates this vulnerability.

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Productinfo

Vendor

• Unstructured-IO

Name

• Unstructured

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24.0

Website

• Product: https://github.com/Unstructured-IO/unstructured/

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