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.
History

Mon, 18 May 2026 12:30:00 +0000

Type Values Removed Values Added
First Time appeared Thecodingmachine
Thecodingmachine gotenberg
CPEs cpe:2.3:a:thecodingmachine:gotenberg:*:*:*:*:*:*:*:*
Vendors & Products Thecodingmachine
Thecodingmachine gotenberg

Fri, 15 May 2026 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 14 May 2026 17:45:00 +0000

Type Values Removed Values Added
First Time appeared Gotenberg
Gotenberg gotenberg
Vendors & Products Gotenberg
Gotenberg gotenberg

Thu, 14 May 2026 16:15:00 +0000

Type Values Removed Values Added
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.
Title Gotenberg: ExifTool group-prefix syntax bypasses dangerous-tag blocklist
Weaknesses CWE-184
References
Metrics cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-05-14T15:36:30.386Z

Updated: 2026-05-15T15:57:55.433Z

Reserved: 2026-04-29T00:31:15.724Z

Link: CVE-2026-42590

cve-icon Vulnrichment

Updated: 2026-05-15T15:56:45.521Z

cve-icon NVD

Status : Analyzed

Published: 2026-05-14T16:16:22.010

Modified: 2026-05-18T12:15:42.390

Link: CVE-2026-42590

cve-icon Redhat

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