Gotenberg up to 8.31.x Internal Service toctou

Summaryinfo

A vulnerability marked as problematic has been reported in Gotenberg up to 8.31.x. Affected by this vulnerability is an unknown functionality of the component Internal Service. This manipulation causes toctou. This vulnerability appears as CVE-2026-42592. The attack may be initiated remotely. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Gotenberg up to 8.31.x. It has been declared as problematic. Affected by this vulnerability is an unknown code of the component Internal Service. The manipulation with an unknown input leads to a toctou vulnerability. The CWE definition for the vulnerability is CWE-367. The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state. As an impact it is known to affect confidentiality. The summary by CVE is:

Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.32.0, 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. This vulnerability is fixed in 8.32.0.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-42592 since 04/29/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available.

Upgrading to version 8.32.0 eliminates this vulnerability.

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Productinfo

Name

• Gotenberg

Version

• 8.0
• 8.1
• 8.2
• 8.3
• 8.4
• 8.5
• 8.6
• 8.7
• 8.8
• 8.9
• 8.10
• 8.11
• 8.12
• 8.13
• 8.14
• 8.15
• 8.16
• 8.17
• 8.18
• 8.19
• 8.20
• 8.21
• 8.22
• 8.23
• 8.24
• 8.25
• 8.26
• 8.27
• 8.28
• 8.29
• 8.30
• 8.31

Website

• Product: https://github.com/gotenberg/gotenberg/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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