Gotenberg has a Server-Side Request Forgery (SSRF) Issue

Exploitation

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

CVSS

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

EPSS

• CVE-2026-42591: 0.25% estimated exploitation activity in the next 30 days; percentile 16.93 (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 The SSRF hardening shipped in v8.31.0 only covers outbound URLs that Gotenberg's Go code handles — Chromium asset fetches, webhook delivery, and download-from. The LibreOffice conversion endpoint (/forms/libreoffice/convert) passes uploaded documents directly to LibreOffice without inspecting their content. LibreOffice then fetches any embedded external URLs on its own, completely bypassing the SSRF filters. This was verified on v8.31.0 (latest at time of writing) with a crafted DOCX and got 3 outbound HTTP requests from LibreOffice to the canary server used for testing. Details When a file is uploaded to /forms/libreoffice/convert, the route in pkg/modules/libreoffice/routes.go reads form parameters and passes the input file directly to libreOffice.Pdf(): There's no content inspection happening before the file reaches LibreOffice. The SSRF protection in v8.31.0 (pkg/gotenberg/outbound.go) wraps Go's http.Client with a custom dialer that resolves URLs and rejects non-public…

Published by the source

7 May 2026, 00:57 UTC

Last modified by the source

14 May 2026, 20:52 UTC

Source last checked

26 Oct 2026, 15:22 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-rm4c-xj6x-49mw

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# Patch Next advisory brief: CVE-2026-42591

Advisory: Gotenberg has a Server-Side Request Forgery (SSRF) Issue
IDs: CVE-2026-42591, GHSA-rm4c-xj6x-49mw
Record: https://patchnext.com/advisories/cve-2026-42591 (revision 1, source checked 26 Oct 2026, 15:22 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/gotenberg/gotenberg/v8: affected <= 8.31.0

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

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## 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-rm4c-xj6x-49mw (GitHub-reviewed advisory GHSA-rm4c-xj6x-49mw lists affected ranges: Go github.com/gotenberg/gotenberg/v8 >=0 <=8.31.0)

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