CVE-2026-79670 json
Ech0 before 4.4.3 Stored XSS via SVG Upload
published 2026-04-10 6 mo ago modified 2026-08-31 2 mo ago also GHSA-69hx-63pv-f8f4 , GO-2026-5172 , EUVD-2026-65444
- cvss
- 4.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 16%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- go github.com/lin-snow/ech0 4.4.3
- lin-snow Ech0 4.4.3
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/lin-snow/Ech0/security/advisories/GHSA-69hx-63pv-f8f4 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 4.8 | CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N |
| CNA | 3.1 | 4.8 | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N |
| CNA | 4.0 | 4.8 | CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| GitHub | 3.1 | 4.8 | CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/lin-snow/ech0 | <4.4.3 all versions |
4.4.3 |
Affected products
- lin-snow Ech0
Classification
- Weakness
-
- CWE-434 Unrestricted Upload of File with Dangerous Type
References
-
github.com
/lin-snow/Ech0/security/advisories/GHSA-69hx-63pv-f8f4
vendor-advisory, exploit, web, advisory
-
vulncheck.com
/advisories/ech0-before-stored-xss-via-svg-upload
third-party-advisory
-
github.com
/lin-snow/Ech0
package
-
github.com
/lin-snow/Ech0/releases/tag/v4.4.3
web
Sources
- CVE List CVE-2026-79670
- GitHub Advisory GHSA-69hx-63pv-f8f4
- NVD CVE-2026-79670
- OSV GO-2026-5172
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.