CVE-2026-40281: Gotenberg vulnerable to argument injection via newlines in ExifTool metadata values

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-05-06 · updated 2026-06-17
Weakness: CWE-88

Description

Gotenberg is a Docker-powered stateless API for PDF files. In versions 8.30.1 and earlier, the metadata write endpoint validates metadata keys for control characters but leaves metadata values unsanitized. A newline character in a metadata value splits the ExifTool stdin line into two separate arguments, allowing injection of arbitrary ExifTool pseudo-tags such as -FileName, -Directory, -SymLink, and -HardLink. This is a bypass of the incomplete key-sanitization fix introduced in v8.30.1. An unauthenticated attacker can rename or move any PDF being processed to an arbitrary path in the container filesystem, overwrite arbitrary files, or create symlinks and hard links at arbitrary paths.

Affected products

gotenberg: before 8.31.0 — fixed in 8.31.0

How to fix

Upgrade to a fixed version: gotenberg 8.31.0. Check the vendor advisory for mitigations.

References

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