CVE-2026-42596 json
Gotenberg: Unauthenticated SSRF via default deny-list bypass in downloadFrom and webhook
published 2026-05-07 6 mo ago modified 2026-06-25 4 mo ago also EUVD-2026-30310 , GHSA-4vmc-gm8v-m35h , GO-2026-5132
- cvss
- 9.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.6%
- EPSS 1.6% chance of exploitation in 30 days, percentile 75%
- public exploits
- 0
- none known, plus a Nuclei check
Summary
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.
Patch / fix
- go github.com/gotenberg/gotenberg/v8 8.32.0
- thecodingmachine gotenberg 8.31.0
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
opensuse advisories openSUSE-SU-2026:21483-1
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 5 mo ago
Exploit prediction
1.59% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- Nuclei template Gotenberg < 8.31.0 - Server-Side Request Forgery nuclei detection template
- github.com https://github.com/gotenberg/gotenberg/security/advisories/GHSA-4vmc-gm8v-m35h referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L |
| GitHub | 3.1 | 9.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/gotenberg/gotenberg/v8 | <8.32.0 |
8.32.0 |
| go | github.com/gotenberg/gotenberg/v7 | all versions |
no fix listed |
Affected products
- gotenberg gotenberg
Classification
- Weakness
-
- CWE-918 Server-Side Request Forgery
References
-
github.com
/gotenberg/gotenberg/security/advisories/GHSA-4vmc-gm8v-m35h
exploit, web, mitigation, vendor-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-42596
advisory
-
github.com
/gotenberg/gotenberg
package
Sources
- CVE List CVE-2026-42596
- GitHub Advisory GHSA-4vmc-gm8v-m35h
- NVD CVE-2026-42596
- OSV GO-2026-5132
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.