CVE-2026-42597: Gotenberg: Chromium URL conversion routes read arbitrary files under /tmp via file:// scheme

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-05-14 · updated 2026-06-17
Weakness: CWE-73

Description

Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.32.0, the /forms/chromium/convert/url and /forms/chromium/screenshot/url routes accept url=file:///tmp/... from anonymous callers. The default Chromium deny-list intentionally exempts file:///tmp/ so HTML/Markdown routes can load their own request-local assets, and those routes apply a per-request AllowedFilePrefixes guard to scope the read. The URL routes never set AllowedFilePrefixes, so the scope guard silently skips. Alice enumerates /tmp/, walks Gotenberg's per-request working directories, and reads the raw source files of other in-flight conversions as rendered PDF output. This vulnerability is fixed in 8.32.0.

Affected products

gotenberg: before 8.32.0 — fixed in 8.32.0

How to fix

Upgrade to a fixed version: gotenberg 8.32.0. Check the vendor advisory for mitigations.

References

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