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CVE-2026-40280· NVD / CVE Program· CNA GitHub_M

Gotenberg SSRF via case-insensitive URL scheme bypass in webhook and downloadFrom deny-lists

Noroxi assessment

Priority: Monitor (action score 32/100)

  • A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
  • Public proof-of-concept code exists (Exploit-DB / GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 2.1% (FIRST EPSS); higher than 81.5% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: gotenberg gotenberg 8.31.0.

Low priority for now. Upgrade to gotenberg gotenberg 8.31.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.8 · v4.0—Proof of concept Fix available
Published
May 5, 2026
Updated
Jul 24, 2026
EPSS
2.1% · 81th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 2.1%

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
7.8
NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-40280

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
thecodingmachinegotenberg

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • thecodingmachine gotenbergbefore 8.31.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • gotenberg gotenberg

    • <= 8.30.1affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Gogithub.com/gotenberg/gotenberg/v7from 0—
Gogithub.com/gotenberg/gotenberg/v7up to and including 7.10.2—
Gogithub.com/gotenberg/gotenberg/v8before 8.31.08.31.0
Gogithub.com/gotenberg/gotenberg/v8before 8.29.08.29.0

Same product

thecodingmachine: all records

Other highest-scoring records for the same primary product.

  • CVE-2020-13450A directory traversal vulnerability in file upload function of Gotenberg through 6.2.1 allows an attacker to upload and overwrite any writab
    41Plan
  • CVE-2026-42589Gotenberg: Unauthenticated RCE via ExifTool Metadata Key Injection
    40Plan
  • CVE-2020-13452In Gotenberg through 6.2.1, insecure permissions for tini (writable by user gotenberg) potentially allow an attacker to overwrite the file,
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-27018Mar 30, 2026 · Gotenberg: Chromium deny-list bypass via case-insensitive URL scheme
    31Monitor
  • ← EarlierCVE-2026-35458Apr 7, 2026 · Gotenberg has a ReDoS via extraHttpHeaders scope feature
    34Monitor
  • Later →CVE-2026-39383May 5, 2026 · Gotenberg unauthenticated blind SSRF via unfiltered webhook URL
    27Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
gotenberg gotenberg8.31.0 · descriptionVendor (CNA)
Go:github.com/gotenberg/gotenberg/v88.29.0Package registry (OSV)
Go:github.com/gotenberg/gotenberg/v88.31.0Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Nuclei detection template ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Nuclei detection templateNuclei template CVE-2026-40280 —

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days+1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-425969 days apartGotenberg: Unauthenticated SSRF via default deny-list bypass in downloadFrom and webhook
    38Monitor
  • CVE-2026-425959 days apartGotenberg: Server-Side Request Forgery via Chromium URL Endpoint with Redirect-Based Deny-List Bypass
    34Monitor
  • CVE-2026-425919 days apartGotenberg: Server-Side Request Forgery (SSRF) in github.com/gotenberg/gotenberg/v8
    32Monitor
  • CVE-2026-393830 days apartGotenberg unauthenticated blind SSRF via unfiltered webhook URL
    27Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-918 · Server-Side Request Forgery (SSRF)

CVSS vector

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records