What is CVE-2026-79670?

CVE-2026-79670 is a medium-severity vulnerability in Lin-Snow Ech0, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 4.8/10. Published 2026-08-25.

How severe is CVE-2026-79670?

Medium severity. CVSS v3 base score is 4.8 out of 10.

Arbitrary file upload in Lin-Snow Ech0

CVE-2026-79670

Ech0 before 4.4.3 contains a stored cross-site scripting vulnerability in the file upload endpoint that validates Content-Type using only client-supplied headers without server-side inspection. Attackers with admin privileges can upload SVG or HTML files containing JavaScript that executes in the application origin when accessed by any user, enabling session hijacking and data exfiltration.

Vulnerability class: Unrestricted File Upload

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.

Affected products

Lin-snow Ech0

Weakness classification (CWE)

CWE-434 — Unrestricted Upload of File with Dangerous Type

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-79670?: CVE-2026-79670 is a medium-severity vulnerability in Lin-Snow Ech0, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 4.8/10. Published 2026-08-25.
How severe is CVE-2026-79670?: Medium severity. CVSS v3 base score is 4.8 out of 10.