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
EPSS: 0.005 (39.0th percentile) — read the EPSS interpretation.
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.
Affected products
- Ech0
- Lin-snow Ech0 — versions < 4.2.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, x_refsource_MISC, 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.