CVSS 4.0
4.8 mediumCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:NCVE-2026-79670
Medium (4.8). EPSS 0.3% chance of exploitation in the next 30 days. Fixed in github.com/lin-snow/ech0 4.4.3.
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.
Severity
CVSS 3.1
4.8 mediumCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N- EPSS
- 0.3% chance of exploitation in the next 30 days; higher than 16% of CVEs (scores of 2026-10-31)
- CWE
- CWE-434
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-69hx-63pv-f8f4 | Go | github.com/lin-snow/ech0 | <4.4.3 | 4.4.3 |
| GO-2026-5172 | Go | github.com/lin-snow/ech0 | all versions | no fix published |