Gotenberg: Server-Side Request Forgery via Chromium URL Endpoint with Redirect-Based Deny-List Bypass

Exploitation

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

CVSS

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

EPSS

• CVE-2026-42595: 0.31% estimated exploitation activity in the next 30 days; percentile 24.23 (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.

A review of 4 published Gotenberg security advisories exposed an SSRF issue. GHSA-pjrr-jgp4-v2fm covers SSRF via the downloadFrom endpoint. GHSA-pcrp-7g9h-7qhp covers SSRF via the webhook endpoint. Neither advisory addresses SSRF through the primary Chromium URL-to-PDF conversion endpoint (/forms/chromium/convert/url), which has no default deny-list for HTTP/HTTPS targets. The redirect-based deny-list bypass described here also applies to downloadFrom and webhook but is a separate finding from the initial request validation those advisories cover. Summary Gotenberg's Chromium URL-to-PDF endpoint (/forms/chromium/convert/url) has no default protection against HTTP/HTTPS-based SSRF. The default deny-list regex only blocks file:// URIs. An unauthenticated attacker can point Chromium at any internal IP — including loopback, RFC 1918 ranges, and cloud metadata endpoints — and receive the response rendered as a PDF. Additionally, even when operators configure a custom deny-list, the…

Published by the source

11 May 2026, 13:51 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-chwh-f6gm-r836

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# Patch Next advisory brief: CVE-2026-42595

Advisory: Gotenberg: Server-Side Request Forgery via Chromium URL Endpoint with Redirect-Based Deny-List Bypass
IDs: CVE-2026-42595, GHSA-chwh-f6gm-r836
Record: https://patchnext.com/advisories/cve-2026-42595 (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 8.6)
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 8.32.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/gotenberg/gotenberg/v8: affected < 8.32.0; fixed in 8.32.0

## 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-chwh-f6gm-r836 (GitHub-reviewed advisory GHSA-chwh-f6gm-r836 lists affected ranges: Go github.com/gotenberg/gotenberg/v8 >=0 <8.32.0)

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