CVE-2026-42596CWE-918

Gotenberg: Unauthenticated SSRF via default deny-list bypass in downloadFrom and webhook

Critical · published May 14, 2026

CVSS v3.1
9.4
EPSS
2%
Percentile
78.0
In the wild
Unconfirmed
What it is

Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.31.0, the default deny-lists used by Gotenberg's downloadFrom feature and webhook feature are bypassable. Because the filter is regex-based and case-sensitive, an unauthenticated attacker can supply URLs such as http://[::ffff:127.0.0.1]:... and reach loopback or private HTTP services that the default deny-list is intended to block. This crosses a real security boundary because an external caller can force the server to make outbound requests to internal-only targets. This vulnerability is fixed in 8.31.0.

The record
Technical detail
CVSS v3.1
9.4 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
CVSS v4.0
Not supplied
EPSS
0.01773 · 78.0th percentile
Weakness
CWE-918 · Server-Side Request Forgery (SSRF)
Published
2026-05-14T15:19Z
EPSS history
Timeline
  • 14 MAY 15:19Z
    Gotenberg: Unauthenticated SSRF via default deny-list bypass in downloadFrom and webhook
    cvelistv5