Gotenberg's DNS rebinding bypasses SSRF validation on Chromium URL conversion routes

Exploitation

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

CVSS

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

EPSS

• CVE-2026-42592: 0.19% estimated exploitation activity in the next 30 days; percentile 8.97 (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 FilterOutboundURL resolves the hostname, checks the resolved IPs against the private-address deny-list, and returns only the error. It discards the resolved addresses. Chromium later performs its own DNS resolution when it navigates to the URL. An attacker who controls DNS for a hostname with a short TTL returns a public IP on the first query (Gotenberg allows) and a private IP on the second query (Chromium connects to the attacker-chosen internal address). The CDP Fetch.requestPaused handler re-checks the URL but runs its own DNS resolution, leaving a timing window before Chromium's actual TCP connect. The rendered internal service response returns to the caller as a PDF. Details pkg/gotenberg/outbound.go:227-230 drops the pinned IPs from the outbound decision: The Chromium convert path at pkg/modules/chromium/browser.go:341 calls FilterOutboundURL(ctx, url, b.arguments.allowList, b.arguments.denyList, deadline) and, on success, hands the raw URL string to Chromium via CDP.…

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-2pmr-289p-44r3

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# Patch Next advisory brief: CVE-2026-42592

Advisory: Gotenberg's DNS rebinding bypasses SSRF validation on Chromium URL conversion routes
IDs: CVE-2026-42592, GHSA-2pmr-289p-44r3
Record: https://patchnext.com/advisories/cve-2026-42592 (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: Medium (CVSS 5.3)
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-2pmr-289p-44r3 (GitHub-reviewed advisory GHSA-2pmr-289p-44r3 lists affected ranges: Go github.com/gotenberg/gotenberg/v8 >=0 <=8.31.0)

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