CVE-2026-40280: Gotenberg is an API-based document conversion tool

Q: How do I fix CVE-2026-40280?

gotenberg: upgrade to 8.31.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-40280 being exploited?

CVE-2026-40280 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-40280 affect?

CVE-2026-40280 affects gotenberg. Severity is high (CVSS 7.5). 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?://) t

Q: How urgent is CVE-2026-40280?

Priority 56/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEUPGRADE

CVE-2026-40280 is a high-severity flaw (CVSS 7.5) affecting gotenberg. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.9% (top 20%)
CISA exploited list	No
Weakness	CWE-918
Published	2026-05-05
Last modified	2026-07-24

Publisher (CNA): GitHub, Inc. · Vendor: thecodingmachine

Last updated 2026-07-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-05 20:16 UTCPublished CVE record published
2026-07-24 21:10 UTCUpdated Record last modified

thecodingmachine gotenberg UPGRADE

Affected: < 8.31.0

Fixed in: 8.31.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy gotenberg || rpm -q gotenberg || gotenberg --version

2. UPGRADE to 8.31.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade gotenberg

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade gotenberg

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Go · github.com/gotenberg/gotenberg/v8 · FIXED · 8.31.0 · vulnerable: <= 8.30.1 · source

go get github.com/gotenberg/gotenberg/v8@v8.31.0 go list -m github.com/gotenberg/gotenberg/v8

Fedora 46 · fzssh · FIXED · 1.4.0-2.fc46 · FEDORA-2026-8004fcd067 · source

sudo dnf upgrade --advisory=FEDORA-2026-8004fcd067

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Nuclei scan template: Gotenberg <= 8.30.1 - Server Side Request Forgery

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-40280?

gotenberg: upgrade to 8.31.0. Exact commands for each OS are on this page.

Is CVE-2026-40280 being exploited?

CVE-2026-40280 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-40280 affect?

CVE-2026-40280 affects gotenberg. Severity is high (CVSS 7.5). 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?://) t

How urgent is CVE-2026-40280?

Priority 56/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-39383 HIGH 7.2 UPGRADE Gotenberg is an API-based document conversion tool
CVE-2026-42597 MEDIUM 5.9 UPGRADE Gotenberg is a Docker-powered stateless API for PDF files
CVE-2026-42596 CRITICAL 9.4 UPGRADE Gotenberg is a Docker-powered stateless API for PDF files
CVE-2026-42595 HIGH 8.6 UPGRADE Gotenberg is a Docker-powered stateless API for PDF files
CVE-2026-42594 HIGH 7.5 UPGRADE Gotenberg is a Docker-powered stateless API for PDF files

References

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