# CVE-2026-27018: Gotenberg has Chromium deny-list bypass via case-insensitive URL scheme (bypass of GHSA-rh2x-ccvw-q7r3)

Source: https://junglewise.ai/threats/cve-2026-27018-gotenberg-has-chromium-deny-list-bypass-via-case-insensitive-url  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-02  
License: CC BY 4.0 with a link back

CVE-2026-27018 · Severity: medium · CVSS 4 · Published 2026-04-02

Gotenberg has Chromium deny-list bypass via case-insensitive URL scheme (bypass of GHSA-rh2x-ccvw-q7r3) in github.com/gotenberg/gotenberg

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). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-27018 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-27018 being exploited in the wild.

**How severe is CVE-2026-27018?** Medium severity, with a CVSS score of 4, published 2 April 2026.

**Which products and versions are affected?** github.com/gotenberg/gotenberg/v7 (Go) SEMVER:introduced=0, SEMVER:introduced=0,last_affected=7.10.2; github.com/gotenberg/gotenberg/v8 (Go) SEMVER:introduced=0,fixed=8.29.0.

**Is there a fix for CVE-2026-27018?** Yes. github.com/gotenberg/gotenberg/v8 (Go): upgrade to 8.29.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-27018?** Check whether you run github.com/gotenberg/gotenberg/v7 (Go) or github.com/gotenberg/gotenberg/v8 (Go) 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 8.29.0 or later

  ```sh
  go get github.com/gotenberg/gotenberg/v8@v8.29.0
  ```


## Affected products

- github.com/gotenberg/gotenberg/v7 (Go) SEMVER:introduced=0, SEMVER:introduced=0,last_affected=7.10.2
- github.com/gotenberg/gotenberg/v8 (Go) SEMVER:introduced=0,fixed=8.29.0

## Identifiers

- CVE-2026-27018
- GHSA-jjwv-57xh-xr6r
- GO-2026-4905

## Related threats

- [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)
- [GO-2026-5587 - Gotenberg has incomplete fix for ExifTool arbitrary file write: case-insensitive bypass and missing…](https://junglewise.ai/threats/go-2026-5587-gotenberg-has-incomplete-fix-for-exiftool-arbitrary-file-5b46f3f0)