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© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2026-40280

32
FAUCET Score

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.

First published: May 5, 2026Last modified: May 6, 2026

Impacted Technologies

VendorProductVersion(s)CPE
< 8.31.0CPE matchmatch criteria
cpe:2.3:a:thecodingmachine:gotenberg:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 4.0

7.8HIGH

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

Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
VS Confidentiality
NONE
VS Integrity
NONE
VS Availability
NONE
SS Confidentiality
HIGH
SS Integrity
LOW
SS Availability
NONE
Exploit Maturity
NOT_DEFINED
CvssVersion
4.0

Exploit Intelligence

EPSS Score
0.46%
Probability of exploitation in next 30 days
EPSS Percentile
37.7%
Percentile rank of EPSS score among Peer Group
As of 2026-07-28
Model: v2026.06.15
This CVE's current EPSS score of 0.0046 is in the 16th percentile among its peer group of 51,553 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (2)

github_advisorypatch availablevia nvd_reference
View patch
gopatch availablevia ghsa
Product: github.com/gotenberg/gotenberg/v8Fixed in: 8.31.0

Vendor Advisories (1)

goGHSA-5q7p-7jgv-ww56high

Gotenberg has case-insensitive URL scheme that bypasses webhook and downloadFrom deny-list SSRF protection

Apr 30, 2026

References

github.com / advisories/GHSA-jjwv-57xh-xr6r
Not Applicable
github.com / gotenberg/gotenberg/commit/3f01ca18d3cc21375a1e2da4b5a3f261c8548e47
Patch
github.com / gotenberg/gotenberg/security/advisories/GHSA-5q7p-7jgv-ww56
ExploitMitigationVendor Advisory