SSRF in Gotenberg
CVE-2026-42596
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.4 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L.
EPSS exploit prediction
EPSS: 0.018 (77.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 77th percentile — 77.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.018 · change: +0.014
Affected products
- Gotenberg — versions < 8.31.0
- Thecodingmachine Gotenberg
Weakness classification (CWE)
References
- github.com/gotenberg/gotenberg/security/advisories/GHSA-4vmc-gm8v-m35h (Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-42596?
- CVE-2026-42596 is a critical-severity vulnerability in Gotenberg, classified under Server-Side Request Forgery (SSRF). CVSS score: 9.4/10. Published 2026-05-14.
- How severe is CVE-2026-42596?
- Critical severity. CVSS v3 base score is 9.4 out of 10.