Auth bypass in Lin-Snow Ech0
CVE-2026-79667
Ech0 version 4.3.4 and earlier fails to reliably enforce scoped access token (least-privilege) restrictions on several privileged admin routes. Multiple privileged endpoints (e.g., /api/inbox, /api/panel/comments, /api/backup/export) omit scope checks and authorize based only on the user's admin role, and the backup export handler discards token scope metadata entirely. An attacker holding a deliberately limited (low-scope) admin access token can reach broader privileged functionality than intended, including reading the inbox and exporting a full database backup ZIP archive. Fixed in 4.4.3.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L.
EPSS exploit prediction
EPSS: 0.003 (23.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 23.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/lin-snow/Ech0/security/advisories/GHSA-4h9q-p5j4-xvvh (vendor-advisory)
- www.vulncheck.com/advisories/ech0-before-authentication-bypass-via-scope-enforc… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-79667?
- CVE-2026-79667 is a high-severity vulnerability in Lin-Snow Ech0, classified under Improper Authorization. CVSS score: 7.6/10. Published 2026-08-25.
- How severe is CVE-2026-79667?
- High severity. CVSS v3 base score is 7.6 out of 10.