CVE-2026-35037
HIGHCVE-2026-35037 is a high-severity (CVSS 7.2) Server-Side Request Forgery (SSRF) vulnerability in github.com/lin-snow/ech0. O3 Security confirms whether CVE-2026-35037 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Ech0 affected by unauthenticated SSRF in GetWebsiteTitle allows access to internal services and cloud metadata
Real-World Exposure
github.com/lin-snow/ech0Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/lin-snow/ech0 | all versions | 1.4.8-0.20260401031029-4ca56fea5ba4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/lin-snow/ech0. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/lin-snow/ech0 to 1.4.8-0.20260401031029-4ca56fea5ba4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-35037 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-35037 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-35037. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-35037 in your dependencies?
O3 detects CVE-2026-35037 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.