CVE-2026-40280
7.5 · HIGHOverview
CVE-2026-40280 is a high-severity vulnerability affecting thecodingmachine gotenberg. It was published on May 5, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from thecodingmachine. Update gotenberg to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| thecodingmachine | gotenberg | >= 0, < 8.31.0 | Affected |
References
Frequently Asked Questions
What is CVE-2026-40280?
CVE-2026-40280 is a high-severity vulnerability affecting thecodingmachine gotenberg. It was published on May 5, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2026-40280?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-40280?
Check the references section for vendor advisories and patches from thecodingmachine. Update gotenberg to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-40280?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-40280 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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