Is CVE-2026-40280 actively exploited?

No active exploitation of CVE-2026-40280 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-40280 be exploited remotely?

Yes. CVE-2026-40280 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-40280?

CVE-2026-40280 has a CVSS score of 7.5 (HIGH).

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HIGH

CVE-2026-40280

CWE-918Published: May 5, 2026· Updated: May 8, 2026

7.5

CVSS v3.1

EPSS:0.04%probability of exploitation in 30 daysPercentile:11.4th

Official 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.

NVD Source

Technical Analysis

CVE-2026-40280 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 7.5.