CVE-2026-40280Public exploitNetwork attack vector

Unauthenticated SSRF via case-sensitive scheme filtering

Published May 5, 2026 · Updated May 5, 2026

SSRF in Gotenberg 8.30.1 and earlier allows remote attackers to reach internal services through webhook and downloadFrom URLs. FilterDeadline applies case-sensitive default deny-list regexes before Go normalizes mixed-case URL schemes and opens the outbound connection. Default unauthenticated API access is sufficient; downloadFrom can return internal content, while webhooks can probe reachable internal endpoints.

CVSS severity7.8
High
EPSS probability1.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

SSRF in Gotenberg 8.30.1 and earlier allows remote attackers to reach internal services through webhook and downloadFrom URLs. FilterDeadline applies case-sensitive default deny-list regexes before Go normalizes mixed-case URL schemes and opens the outbound connection. Default unauthenticated API access is sufficient; downloadFrom can return internal content, while webhooks can probe reachable internal endpoints.

The record

CVE
CVE-2026-40280
Published
May 5, 2026
Updated
May 5, 2026
Vendor
Gotenberg
Product
Gotenberg
Classifications
CWE-918, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 5, 2026CVE publishedPublication date reported by the CVE source.
  2. May 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<= 8.30.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Gotenberg · Gotenbergversion=<= 8.30.1

Published CVSS scores

7.8GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo