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OpenAdvisories
High · 8.2 CVE-2026-42590 EUVD-2026-30316GHSA-7v3r-m9c8-r855GO-2026-5234

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

Published May 14, 2026 · Updated May 15, 2026 · Assigned by GitHub_M

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

VendorProductAffectedFixed
gotenberg gotenberg < 8.30.0 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/gotenberg/gotenberg/v7 all versions — GO-2026-5234
Go github.com/gotenberg/gotenberg/v8 <= 8.29.1 — GHSA-7v3r-m9c8-r855
Go github.com/gotenberg/gotenberg/v8 all versions — GO-2026-5234

Advisories 1

References