CVE-2026-42596
Prior to 8.31.0, the default deny-lists used by Gotenberg's downloadFrom feature and webhook feature are bypassable.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.24%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 9.4 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
- EPSS
- 1.24% probability · 67th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-918
- Affected
- thecodingmachine/gotenberg
- Source
- security-advisories@github.com
References
- https://github.com/gotenberg/gotenberg/security/advisories/GHSA-4vmc-gm8v-m35hExploit, Mitigation, Vendor Advisory
- https://github.com/gotenberg/gotenberg/security/advisories/GHSA-4vmc-gm8v-m35hExploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.