CVE-2026-35036
HIGHCVE-2026-35036 is a high-severity (CVSS 7.5) Server-Side Request Forgery (SSRF) vulnerability in github.com/lin-snow/ech0. O3 Security confirms whether CVE-2026-35036 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Ech0 Affected by Unauthenticated Server-Side Request Forgery in Website Preview Feature
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, Ech0 implements link preview (editor fetches a page title) through GET /api/website/title. That is legitimate product behavior, but the implementation is unsafe: the route is unauthenticated, accepts a fully attacker-controlled URL, performs a server-side GET, reads the entire response body into memory (io.ReadAll). There is no host allowlist, no SSRF filter, and InsecureSkipVerify: true on the outbound client. Anyone who can reach the instance can force the Ech0 server to open HTTP/HTTPS URLs of their choice as seen from the server’s network position (Docker bridge, VPC, localhost from the process view). 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-2026-35036 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-2026-35036 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-2026-35036. 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-2026-35036 in your dependencies?
O3 detects CVE-2026-35036 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.