# CVE-2026-40281: Gotenberg argument injection in metadata write endpoint

Source: https://junglewise.ai/threats/cve-2026-40281-gotenberg-argument-injection-in-metadata-write-endpoint  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-06. Updated: 2026-05-11  
License: CC BY 4.0 with a link back

CVE-2026-40281 · Severity: critical · CVSS 10 · Published 2026-05-06

Gotenberg is a specialized tool used to convert various file formats into PDFs via a web API. A security flaw in its metadata processing allows an attacker to manipulate how files are saved within the system. By sending a specially crafted request, an unauthenticated user could move, rename, or overwrite critical system files, potentially leading to a complete service disruption or unauthorized system modifications.

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-2026-40281 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-40281 being exploited in the wild.

**How severe is CVE-2026-40281?** Critical severity, with a CVSS score of 10, published 6 May 2026.

**Which products and versions are affected?** github.com/gotenberg/gotenberg/v7 (Go) SEMVER:introduced=0; github.com/gotenberg/gotenberg/v8 (Go) SEMVER:introduced=0,fixed=8.31.0; Gotenberg <= 8.30.1.

**Is there a fix for CVE-2026-40281?** Yes. github.com/gotenberg/gotenberg/v8 (Go): upgrade to 8.31.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-40281 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-40281?** 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.

## How to fix

- github.com/gotenberg/gotenberg/v8 (Go): upgrade to 8.31.0 or later

  ```sh
  go get github.com/gotenberg/gotenberg/v8@v8.31.0
  ```


## Technical details

The vulnerability exists in the metadata write endpoint where metadata values are not properly sanitized before being passed to ExifTool via the go-exiftool library. While a previous fix (v8.30.1) implemented sanitization for metadata keys, it failed to sanitize metadata values. An attacker can inject a newline character (\n) into a metadata value, which causes the underlying line-based stdin protocol of ExifTool to interpret the subsequent data as new command-line arguments. This allows the injection of dangerous pseudo-tags such as -FileName, -Directory, -SymLink, and -HardLink. Exploitation can lead to arbitrary file overwrites or the creation of symlinks/hardlinks within the container. The issue is addressed in version 8.31.0.

## Affected products

- Gotenberg Gotenberg <= 8.30.1

## Identifiers

- CVE-2026-40281
- GHSA-q7r4-hc83-hf2q
- GO-2026-5572

## Timeline

- 2026-04-30: advisory: GitHub Security Advisory published
- 2026-05-06: disclosed: CVE-2026-40281 published to NVD
- 2026-05-11: patched: NVD analysis and CPE information updated

## References

- [https://github.com/gotenberg/gotenberg/commit/405f1069c026bb08f319fb5a44e5c67c33208318](https://github.com/gotenberg/gotenberg/commit/405f1069c026bb08f319fb5a44e5c67c33208318)
- [https://github.com/gotenberg/gotenberg/security/advisories/GHSA-q7r4-hc83-hf2q](https://github.com/gotenberg/gotenberg/security/advisories/GHSA-q7r4-hc83-hf2q)

## 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)