SSRF in Ech0
CVE-2026-35036
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (36.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Ech0
- Lin-Snow Ech0 — versions < 4.2.8
Weakness classification (CWE)
References
- github.com/lin-snow/Ech0/security/advisories/GHSA-wc4h-2348-jc3p (Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-35036?
- CVE-2026-35036 is a high-severity vulnerability in Ech0, classified under Server-Side Request Forgery (SSRF). CVSS score: 7.5/10. Published 2026-04-06.
- How severe is CVE-2026-35036?
- High severity. CVSS v3 base score is 7.5 out of 10.