Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| lin-snow | Ech0 | < 4.4.3 | 4.4.3 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/lin-snow/ech0 | < 4.4.3 | 4.4.3 | GHSA-69hx-63pv-f8f4 |
| Go | github.com/lin-snow/ech0 | all versions | — | GO-2026-5172 |
References
- GitHub Security Advisory (GHSA-69hx-63pv-f8f4) vendor-advisory
- VulnCheck Advisory: Ech0 before 4.4.3 Stored XSS via SVG Upload third-party-advisory