CVE-2026-42590 Gotenberg: ExifTool group-prefix syntax bypasses dangerous-tag blocklist
Attackers can bypass metadata blocklists to rename, move, or link files on the server, potentially leading to code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42590?
CVE-2026-42590 is a high-severity path traversal vulnerability in gotenberg, published on 14 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.30.0, The ExifTool metadata write blocklist in Gotenberg can be bypassed using ExifTool's group-prefix syntax, enabling arbitrary file rename, move, hardlink, and symlink creation on the server. ExifTool supports group-prefix syntax where File:FileName is processed identically to FileName -- the prefix is stripped by SetNewValue in Writer.pl before tag matching. The safeKeyPattern regex (^[a-zA-Z0-9\-_.:]+$) allows colons, so prefixed tag names pass validation. Any prefix works: File:FileName, System:Directory, a:HardLink, etc. Additionally, FilePermissions, FileUserID, and FileGroupID pseudo-tags are not blocked at all and can modify file attributes without any prefix. This vulnerability is fixed in 8.30.0.
Weakness: CWE-184
Which versions are affected by CVE-2026-42590?
4 open source packages ship an affected version, including github.com/gotenberg/gotenberg/v8 and github.com/gotenberg/gotenberg/v7. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/gotenberg/gotenberg/v8 Go | All versions | None |
github.com/gotenberg/gotenberg/v8 Go | All versions to 8.29.1 | None |
github.com/gotenberg/gotenberg/v8 Go | All versions to 8.29.1 | None |
github.com/gotenberg/gotenberg/v7 Go | All versions | None |
Products include Thecodingmachine Gotenberg.
How do I fix CVE-2026-42590?
Upgrade to a fixed version.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-42590 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42590 exists.
Other vulnerabilities in gotenberg
Sources
Also known as GHSA-7v3r-m9c8-r855, GO-2026-5234.