CVE-2026-35037: Ech0: Unauthenticated SSRF in GetWebsiteTitle allows access to internal services and cloud metadata

CVE-2026-35037 · Severity: high · CVSS 7.2 · Published 2026-04-06

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.

Technologies: github.com/lin-snow/ech0 (Go). Vendors: Go.

Quick answers

Is CVE-2026-35037 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-35037 being exploited in the wild.
How severe is CVE-2026-35037?
High severity, with a CVSS score of 7.2, published 6 April 2026.
Which products and versions are affected?
github.com/lin-snow/ech0 (Go) SEMVER:introduced=0,fixed=1.4.8-0.20260401031029-4ca56fea5ba4.
Is there a fix for CVE-2026-35037?
Yes. github.com/lin-snow/ech0 (Go): upgrade to 1.4.8-0.20260401031029-4ca56fea5ba4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-35037?
Check whether you run Ech0 or github.com/lin-snow/ech0 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/lin-snow/ech0 (Go): upgrade to 1.4.8-0.20260401031029-4ca56fea5ba4 or later
    go get github.com/lin-snow/ech0@v1.4.8-0.20260401031029-4ca56fea5ba4

Affected products

  • Ech0
  • github.com/lin-snow/ech0 (Go) SEMVER:introduced=0,fixed=1.4.8-0.20260401031029-4ca56fea5ba4

Identifiers

  • CVE-2026-35037
  • GHSA-cqgf-f4x7-g6wc
  • GO-2026-5331

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