Read the docs
TI-2026-30870 Aliases CVE-2026-42590GHSA-7v3r-m9c8-r855

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

Priority HIGH 75CWE-184Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · High · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.0029 21st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed gotenberg (gotenberg): 8.30.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
gotenberggotenbergbefore 8.30.08.30.0Patch availableCNA
—github.com/gotenberg/gotenberg/v8 (Go)up to 8.29.1—No fix listedGHSA-7v3r-m9c8-r855
  • gotenberg Vendorgotenberg Affected before 8.30.0 Fixed in 8.30.0 Patch available CNA
  • github.com/gotenberg/gotenberg/v8 (Go) Vendor— Affected up to 8.29.1 Fixed in — No fix listed GHSA-7v3r-m9c8-r855

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:thecodingmachine:gotenberg:*:*:*:*:*:*:*:*before 8.30.0Vulnerablegotenberg
  • cpe:2.3:a:thecodingmachine:gotenberg:*:*:*:*:*:*:*:* Versions before 8.30.0 Vulnerable ·gotenberg

Remediation

  • Fix · CNA gotenberg (gotenberg) Fixed in 8.30.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-42590
  2. 2026-10-03 Alias added: GHSA-7v3r-m9c8-r855

References

Exploit 1

Advisory 2

Other 1

  • TI-2026-30869 Gotenberg: Unauthenticated RCE via ExifTool Metadata Key Injection CVSS 3.1CRITICAL 9.8
  • TI-2026-29063 Gotenberg vulnerable to argument injection via newlines in ExifTool metadata values CVSS 3.1CRITICAL 10.0
  • TI-2026-30876 Gotenberg: Unauthenticated SSRF via default deny-list bypass in downloadFrom and webhook CVSS 3.1CRITICAL 9.4
  • TI-2026-27588 Gotenberg has a ReDoS via extraHttpHeaders scope feature CVSS 4.0HIGH 8.7
  • TI-2026-30875 Gotenberg: Server-Side Request Forgery via Chromium URL Endpoint with Redirect-Based Deny-List Bypass CVSS 3.1HIGH 8.6
  • TI-2026-30871 Gotenberg: Server-Side Request Forgery (SSRF) in github.com/gotenberg/gotenberg/v8 CVSS 3.1HIGH 8.2
See all 21 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences