Gotenberg Vulnerable to Unauthenticated SSRF via Unfiltered Webhook URL

Exploitation

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

CVSS 4.0

6.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N · score source

EPSS

• CVE-2026-39383: 0.24% estimated exploitation activity in the next 30 days; percentile 14.74 (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.

CVE Report — Unauthenticated SSRF via Unfiltered Webhook URL in Gotenberg Severity | Field | Value | |-----------|----------------------------------------| | CVSS v3.1 | 8.6 High | | Vector | AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N | | CWE | CWE-918 — Server-Side Request Forgery | | Auth | None | Affected: Gotenberg 8.29.1 — default gotenberg/gotenberg:8 Docker image. --- Impact An unauthenticated attacker with network access to Gotenberg can force it to make outbound HTTP POST requests to any internal or external destination by supplying an arbitrary URL in the Gotenberg-Webhook-Url request header. This is a blind SSRF. Gotenberg POSTs the converted document to the webhook URL and checks only whether the response status code is an error (= 400). The response body from the SSRF target is never forwarded to the attacker. The Gotenberg-Webhook-Error-Url header — if supplied — receives the original converted PDF when the webhook POST fails, not the target's response body. The practical…

Published by the source

30 Apr 2026, 17:24 UTC

Last modified by the source

8 May 2026, 15:31 UTC

Source last checked

26 Oct 2026, 15:20 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-5vh4-rgv7-p9g4

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# Patch Next advisory brief: CVE-2026-39383

Advisory: Gotenberg Vulnerable to Unauthenticated SSRF via Unfiltered Webhook URL
IDs: CVE-2026-39383, GHSA-5vh4-rgv7-p9g4
Record: https://patchnext.com/advisories/cve-2026-39383 (revision 1, source checked 26 Oct 2026, 15:20 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
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 8.31.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/gotenberg/gotenberg/v8: affected >= 8.29.1, < 8.31.0; fixed in 8.31.0

## 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-5vh4-rgv7-p9g4 (GitHub-reviewed advisory GHSA-5vh4-rgv7-p9g4 lists affected ranges: Go github.com/gotenberg/gotenberg/v8 >=8.29.1 <8.31.0)

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