Auth bypass in Ech0
CVE-2026-33638
Ech0 is an open-source, self-hosted publishing platform for personal idea sharing. Prior to version 4.2.0, `GET /api/allusers` is mounted as a public endpoint and returns user records without authentication. This allows remote unauthenticated user enumeration and exposure of user profile metadata. A fix is available in v4.2.0.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.006 (47.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 47.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.001
Affected products
- Ech0
- Lin-Snow Ech0 — versions < 4.2.0
Weakness classification (CWE)
References
- github.com/lin-snow/Ech0/security/advisories/GHSA-m983-7426-5hrj (Vendor Advisory)
- github.com/lin-snow/Ech0/commit/acbf1fd71011e6b9e1e6a911128056a19862f681 (Patch)
- github.com/lin-snow/Ech0/releases/tag/v4.2.0 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-33638?
- CVE-2026-33638 is a medium-severity vulnerability in Ech0, classified under Missing Authorization. CVSS score: 5.3/10. Published 2026-03-26.
- How severe is CVE-2026-33638?
- Medium severity. CVSS v3 base score is 5.3 out of 10.