CVE-2026-42589
CriticalSummary
Gotenberg is a PDF file API that, prior to version 8.31.0, did not validate keys in JSON objects sent to the /forms/pdfengines/metadata/write endpoint. Using a newline character in a JSON key allows for the injection of arbitrary ExifTool flags, leading to unauthenticated OS command execution.
Risk Assessment
An attacker can gain access to the operating system by executing arbitrary commands, posing a serious security threat to the organization. Additionally, the attack response is difficult to detect as it returns a valid PDF file.
Recommendation
It is recommended to update Gotenberg to version 8.31.0 or later to eliminate this vulnerability. Consider implementing additional monitoring and input validation mechanisms.
Other vulnerabilities in Gotenberg API
See all- CVE-2026-42594High
Gotenberg, a PDF file API, has a vulnerability prior to version 8.32.0 that can lead to process crashes. The issue arises from improper context management during concurrent requests, causing a panic in the webhook goroutine.
- CVE-2026-42591High
Gotenberg is a stateless API for PDF files that, prior to version 8.32.0, passed uploaded documents directly to LibreOffice without inspecting their content. LibreOffice then fetched any embedded external URLs on its own, completely bypassing SSRF filters.
- CVE-2026-42596Critical
Gotenberg is an API for PDF files that prior to version 8.31.0 had a vulnerability in the downloadFrom and webhook features. The default deny-lists were bypassable, allowing unauthenticated attackers to access internal HTTP services.
- CVE-2026-40281Critical
Gotenberg is a stateless API for PDF files that in versions 8.30.1 and earlier improperly validates metadata values. These values can contain newline characters, allowing injection of arbitrary ExifTool pseudo-tags, leading to serious security vulnerabilities.
Original NVD description (English source)
Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.31.0, Gotenberg's /forms/pdfengines/metadata/write HTTP endpoint accepts a JSON metadata object and passes its keys directly to ExifTool via the go-exiftool library. No validation is performed on key characters. A \n embedded in a JSON key splits the ExifTool stdin stream into a new argument line, allowing an attacker to inject arbitrary ExifTool flags — including -if, which evaluates Perl expressions. This achieves unauthenticated OS command execution in a single HTTP request. The response is HTTP 200 with a valid PDF, making the attack transparent to basic monitoring. This vulnerability is fixed in 8.31.0.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS