Gotenberg allows Chromium URL conversion routes to read arbitrary files under /tmp via file:// scheme

Exploitation

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

CVSS

5.9 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-42597: 0.28% estimated exploitation activity in the next 30 days; percentile 20.26 (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 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. Details The default deny-list regex at pkg/modules/chromium/chromium.go:449 uses a negative lookahead to exempt /tmp/: pkg/gotenberg/outbound.go:185-187 short-circuits IP validation for non-HTTP schemes: So any file:///tmp/... URL passes FilterOutboundURL cleanly. The HTML route pairs the exemption with a per-request scope guard (pkg/modules/chromium/routes.go:518): and the CDP Fetch.requestPaused handler…

Published by the source

7 May 2026, 01:15 UTC

Last modified by the source

21 Jul 2026, 14:34 UTC

Source last checked

26 Oct 2026, 15:27 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-g924-cjx7-2rjw

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# Patch Next advisory brief: CVE-2026-42597

Advisory: Gotenberg allows Chromium URL conversion routes to read arbitrary files under /tmp via file:// scheme
IDs: CVE-2026-42597, GHSA-g924-cjx7-2rjw
Record: https://patchnext.com/advisories/cve-2026-42597 (revision 1, source checked 26 Oct 2026, 15:27 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Partial vendor fix; fixed versions by package: github.com/gotenberg/gotenberg/v8 8.32.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/gotenberg/gotenberg/v7: affected <= 7.10.2
- Go github.com/gotenberg/gotenberg/v8: affected <= 8.31.0; fixed in 8.32.0

## Suggested inspection (read-only)
- Go github.com/gotenberg/gotenberg/v7: check the installed version with your package manager.
- 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/v7, 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-g924-cjx7-2rjw (GitHub-reviewed advisory GHSA-g924-cjx7-2rjw lists affected ranges: Go github.com/gotenberg/gotenberg/v8 >=0 =0 <=7.10.2)

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