Description
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.
INFO
Published Date :
2026-05-05T19:52:40.327Z
Last Modified :
2026-05-05T19:52:40.327Z
Source :
GitHub_M
AFFECTED PRODUCTS
The following products are affected by CVE-2026-40280 vulnerability.
| Vendors | Products |
|---|---|
| Gotenberg |
|
REFERENCES
Here, you will find a curated list of external links that provide in-depth information to CVE-2026-40280.
