Gotenberg is an API-based document conversion tool. In versions 8.30.1 and earlier, the default private-IP deny-lists for the --webhook-deny-list and --api-download-from-deny-list flags use a case-sensitive regular expression (^https?://) to match URL schemes. Because Go's net/url.Parse() normalizes the scheme to lowercase before establishing the outbound TCP connection, an attacker can bypass the deny-list by simply capitalizing part of the URL scheme (e.g., HTTP://, HTTPS://, or Http://). This allows unauthenticated requests to reach internal network services, including private IP ranges, loopback addresses, and cloud instance metadata endpoints such as HTTP://169.254.169.254/latest/meta-data/.
This bypasses the same security control that was patched in CVE-2026-27018.
This issue has been fixed in version 8.31.0.
References
| Link | Resource |
|---|---|
| https://github.com/advisories/GHSA-jjwv-57xh-xr6r | Not Applicable |
| https://github.com/gotenberg/gotenberg/commit/3f01ca18d3cc21375a1e2da4b5a3f261c8548e47 | Patch |
| https://github.com/gotenberg/gotenberg/security/advisories/GHSA-5q7p-7jgv-ww56 | Exploit Mitigation Vendor Advisory |
| https://github.com/gotenberg/gotenberg/security/advisories/GHSA-5q7p-7jgv-ww56 | Exploit Mitigation Vendor Advisory |
Configurations
History
08 May 2026, 19:06
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/advisories/GHSA-jjwv-57xh-xr6r - Not Applicable | |
| References | () https://github.com/gotenberg/gotenberg/commit/3f01ca18d3cc21375a1e2da4b5a3f261c8548e47 - Patch | |
| References | () https://github.com/gotenberg/gotenberg/security/advisories/GHSA-5q7p-7jgv-ww56 - Exploit, Mitigation, Vendor Advisory | |
| First Time |
Thecodingmachine gotenberg
Thecodingmachine |
|
| CPE | cpe:2.3:a:thecodingmachine:gotenberg:*:*:*:*:*:*:*:* | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.5 |
06 May 2026, 19:16
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/gotenberg/gotenberg/security/advisories/GHSA-5q7p-7jgv-ww56 - |
05 May 2026, 20:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-05 20:16
Updated : 2026-05-08 19:06
NVD link : CVE-2026-40280
Mitre link : CVE-2026-40280
CVE.ORG link : CVE-2026-40280
JSON object : View
Products Affected
thecodingmachine
- gotenberg
CWE
CWE-918
Server-Side Request Forgery (SSRF)
