CVE-2026-105742: Docling Remote Image Header Exposure Vulnerability
Summary
CVE-2026-105742: Docling: Configured HTTP headers sent to every remote image host named by a document. Affects docling versions >= 2.95.0, < 2.132.0. Fixed in 2.132.0. How to fix ↓
Also tracked for
- docling-slim · PyPI
The same CVE-2026-105742 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
Docling is an open-source tool designed for converting HTML documents into various formats while allowing for the inclusion of remote images. It provides options for fetching images from external sources, which can be configured to include authentication headers such as API keys and bearer tokens. However, this functionality can lead to security risks if not properly managed, particularly when handling untrusted documents.
Vulnerability Detail
The vulnerability arises from the way Docling handles HTTP headers when fetching remote images. Specifically, the HTMLBackendOptions.headers configuration allows users to pass authentication headers that are sent with every remote image request. This means that if an untrusted document references an attacker-controlled image URL, the caller's credentials are inadvertently exposed to the attacker. The underlying issue is that the headers are merged into each remote request without validating the destination against the source document's origin, leading to potential credential leakage.
How To Fix
Latest published version: 2.142.0 as of 22 Oct 2026
pip install --upgrade "docling==2.142.0"Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
2.132.0
This is the first release that contains the fix.
pip install --upgrade "docling==2.132.0"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
For users unable to upgrade to the patched version, a temporary workaround is to avoid setting the headers option when converting untrusted documents. Alternatively, use credentials that are valid only for the intended host and have no other value.
Conclusion
The CVE-2026-105742 vulnerability in Docling poses a risk of exposing sensitive HTTP headers when fetching remote images from untrusted sources. Users are advised to upgrade to the patched version to mitigate this risk effectively. For those unable to upgrade, specific workarounds can help reduce exposure.
See every vulnerability recorded for docling →
FAQ
CVE-2026-105742 is a vulnerability in Docling that exposes configured HTTP headers, including sensitive credentials, to untrusted remote image hosts.
If your application uses Docling with the headers option set while converting untrusted HTML documents, it may inadvertently send sensitive credentials to attacker-controlled hosts.
If an upgrade is not possible, avoid using the headers option with untrusted documents or use limited-scope credentials that are safe for the intended host.
You can use Vulert's playground at Vulert Scanner to monitor and check for open-source vulnerabilities in your application without needing to sign up.
The CVSS score for this vulnerability is 3.7, indicating a low severity level.
References
Related vulnerabilities
Recent vulnerabilities recorded for docling.
