docling-project docling/docling-slim up to 2.131.x URL Validation image_resource_loader.py validate_url_safety dns rebinding

Summaryinfo

A vulnerability, which was classified as problematic, has been found in docling-project docling and docling-slim up to 2.131.x. The impacted element is the function validate_url_safety of the file docling/backend/utils/image_resource_loader.py of the component URL Validation. This manipulation causes dns rebinding. This vulnerability is tracked as CVE-2026-105743. The attack is possible to be carried out remotely. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in docling-project docling and docling-slim up to 2.131.x. It has been declared as problematic. Affected by this vulnerability is the function validate_url_safety of the file docling/backend/utils/image_resource_loader.py of the component URL Validation. The manipulation with an unknown input leads to a dns rebinding vulnerability. The CWE definition for the vulnerability is CWE-350. The product performs reverse DNS resolution on an IP address to obtain the hostname and make a security decision, but it does not properly ensure that the IP address is truly associated with the hostname. As an impact it is known to affect confidentiality. The summary by CVE is:

Docling simplifies document processing by parsing diverse formats and providing integrations with the generative AI ecosystem. From 2.91.0 until 2.132.0, validate_url_safety in docling/backend/utils/image_resource_loader.py validates a hostname with a single IPv4 lookup and then allows the HTTP client to resolve and parse the original URL again, permitting DNS rebinding, mixed public and internal address records, and backslash authority parser disagreement to reach internal services. HTMLBackendOptions(render_page=True) also allows HTTP and HTTPS browser requests without validating their resolved destination. Exploitation requires remote fetching to be enabled, and response content is exposed only when it is decoded as an image or passively rendered in a page screenshot. This issue is fixed in 2.132.0.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-105743 since 10/05/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1583.002 according to MITRE ATT&CK.

Upgrading to version 2.132.0 eliminates this vulnerability.

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Productinfo

Type

• Project Management Software

Vendor

• docling-project

Name

• docling
• docling-slim

Version

• 2.131

Website

• Product: https://github.com/docling-project/docling/

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CPE 2.2info

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