# CVE-2026-42591: Gotenberg SSRF in LibreOffice conversion endpoint

Source: https://junglewise.ai/threats/cve-2026-42591-gotenberg-ssrf-in-libreoffice-conversion-endpoint  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-14. Updated: 2026-05-18  
License: CC BY 4.0 with a link back

CVE-2026-42591 · Severity: high · CVSS 8.2 · Published 2026-05-14

Gotenberg is a tool used to convert various document formats into PDF files via a web interface. A security flaw allows attackers to upload specially crafted documents that force the server to make unauthorized network requests to internal systems or cloud metadata services. This could lead to the theft of sensitive credentials or the exposure of private internal data that is otherwise inaccessible from the internet.

Technologies: [github.com/gotenberg/gotenberg/v7 (Go)](https://junglewise.ai/threats/technologies/github-com-gotenberg-gotenberg-v7), [github.com/gotenberg/gotenberg/v8 (Go)](https://junglewise.ai/threats/technologies/github-com-gotenberg-gotenberg-v8), [Gotenberg](https://junglewise.ai/threats/technologies/gotenberg). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Gotenberg](https://junglewise.ai/threats/vendors/gotenberg).

## Quick answers

**Is CVE-2026-42591 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-42591 being exploited in the wild.

**How severe is CVE-2026-42591?** High severity, with a CVSS score of 8.2, published 14 May 2026.

**Which products and versions are affected?** github.com/gotenberg/gotenberg/v7 (Go) SEMVER:introduced=0; github.com/gotenberg/gotenberg/v8 (Go) <= 8.31.0, SEMVER:introduced=0, SEMVER:introduced=0,last_affected=8.31.0; Gotenberg < 8.32.0, <= 8.31.0.

**Is there a fix for CVE-2026-42591?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-42591 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-42591?** Check whether you run github.com/gotenberg/gotenberg/v7 (Go), github.com/gotenberg/gotenberg/v8 (Go) or Gotenberg at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A Server-Side Request Forgery (SSRF) vulnerability exists in Gotenberg's LibreOffice conversion endpoint (/forms/libreoffice/convert). While Gotenberg implemented SSRF hardening in version 8.31.0 for its Go-based components, the LibreOffice subprocess operates independently and bypasses these filters when processing documents with embedded external URLs (e.g., OOXML files with 'External' TargetMode relationships). An unauthenticated remote attacker can upload a crafted document (DOCX, XLSX, etc.) containing external references, causing the LibreOffice process to fetch remote content. This can be used to exfiltrate data from internal services, access cloud metadata (169.254.169.254), or perform internal port scanning. The issue is resolved in version 8.32.0 by isolating the LibreOffice process network namespace.

## Affected products

- Gotenberg Gotenberg <= 8.31.0

## Identifiers

- CVE-2026-42591
- GHSA-rm4c-xj6x-49mw
- GO-2026-5627

## Timeline

- 2026-04-30: advisory: GitHub Security Advisory published
- 2026-05-14: disclosed: CVE published to NVD

## References

- [https://github.com/gotenberg/gotenberg/security/advisories/GHSA-rm4c-xj6x-49mw](https://github.com/gotenberg/gotenberg/security/advisories/GHSA-rm4c-xj6x-49mw)

## Related threats

- [Gotenberg server-side request forgery in IsPublicIP IPv6 handling](https://junglewise.ai/threats/cve-2026-126799-gotenberg-8-31-0-before-8-38-0-contains-a-server-side-request)
- [Gotenberg race condition in multipart downloadFrom handling](https://junglewise.ai/threats/cve-2026-45742-gotenberg-race-condition-in-multipart-downloadfrom-handling)
- [Gotenberg SSRF deny-list bypass in IsPublicIP via IPv6 prefixes](https://junglewise.ai/threats/cve-2026-45741-gotenberg-ssrf-deny-list-bypass-in-ispublicip-via-ipv6-prefixes)
- [Gotenberg path traversal via Windows-style separators in ZIP entry names](https://junglewise.ai/threats/cve-2026-44829-gotenberg-path-traversal-via-windows-style-separators-in-zip)
- [Gotenberg SSRF and local file disclosure in LibreOffice conversion](https://junglewise.ai/threats/cve-2026-55229-gotenberg-ssrf-and-local-file-disclosure-in-libreoffice)