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CVE PROGRAM SOURCE RECORD8.2 High

CVE-2026-42590

Gotenberg: ExifTool group-prefix syntax bypasses dangerous-tag blocklist

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

gotenberg gotenberg

  • < 8.30.0affected

References