TI-2026-27240 Aliases CVE-2026-35037 GHSA-cqgf-f4x7-g6wc

Ech0 affected by unauthenticated SSRF in GetWebsiteTitle allows access to internal services and cloud metadata

HIGH 71CWE-918Published 2026-04-06 · Updated 2026-04-06

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: Low · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

Ech0 is an open-source, self-hosted publishing platform for personal idea sharing. Prior to 4.2.8, the GET /api/website/title endpoint accepts an arbitrary URL via the website_url query parameter and makes a server-side HTTP request to it without any validation of the target host or IP address. The endpoint requires no authentication. An attacker can use this to reach internal network services, cloud metadata endpoints (169.254.169.254), and localhost-bound services, with partial response data exfiltrated via the HTML <title> tag extraction This vulnerability is fixed in 4.2.8.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00618 49th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed Ech0 (lin-snow): 4.2.8github.com/lin-snow/ech0 (Go): 1.4.8-0.20260401031029-4ca56fea5ba4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
lin-snow	Ech0	before 4.2.8	4.2.8	Patch available	CNA
—	github.com/lin-snow/ech0 (Go)	before 1.4.8-0.20260401031029-4ca56fea5ba4	1.4.8-0.20260401031029-4ca56fea5ba4	Patch available	GHSA-cqgf-f4x7-g6wc

Ech0 Vendorlin-snow Affected before 4.2.8 Fixed in 4.2.8 Patch available CNA
github.com/lin-snow/ech0 (Go) Vendor— Affected before 1.4.8-0.20260401031029-4ca56fea5ba4 Fixed in 1.4.8-0.20260401031029-4ca56fea5ba4 Patch available GHSA-cqgf-f4x7-g6wc

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:ech0:ech0::::::::	before 4.2.8	Vulnerable	lin-snow

cpe:2.3:a:ech0:ech0:*:*:*:*:*:*:*:* Versions before 4.2.8 Vulnerable ·lin-snow

Remediation

Fix · CNA Ech0 (lin-snow) Fixed in 4.2.8
Fix · GHSA-cqgf-f4x7-g6wc github.com/lin-snow/ech0 (Go) Fixed in 1.4.8-0.20260401031029-4ca56fea5ba4 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-35037
2026-10-03 Alias added: GHSA-cqgf-f4x7-g6wc
2026-10-25 EPSS moved to the below the 50th percentile

References

TI-2026-27239 Ech0 Affected by Unauthenticated Server-Side Request Forgery in Website Preview Feature CVSS 3.1HIGH 7.5
TI-2026-26019 Ech0 authenticated user-list exposed data via public `/api/allusers` endpoint CVSS 3.1MEDIUM 5.3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences