{"cve":"CVE-2026-79670","nvd":{"published":"2026-08-25T12:16:35.247","modified":"2026-08-31T20:52:56.343","status":"Deferred","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.","cvss_v4":{"vector":"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","score":4.8},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N","score":4.8},"cwes":["CWE-434"],"references":["https://github.com/lin-snow/Ech0/security/advisories/GHSA-69hx-63pv-f8f4","https://www.vulncheck.com/advisories/ech0-before-stored-xss-via-svg-upload","https://github.com/lin-snow/Ech0/security/advisories/GHSA-69hx-63pv-f8f4"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:50:17.453294893+00:00"},"epss":{"cve":"CVE-2026-79670","score":0.00251,"percentile":0.16662,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-69hx-63pv-f8f4","url":"https://osv.dev/vulnerability/GHSA-69hx-63pv-f8f4","summary":"Ech0 has Stored XSS via SVG Upload and Content-Type Validation Bypass in File Upload","modified":"2026-08-27T04:10:33.767398467Z","packages":[{"ecosystem":"Go","name":"github.com/lin-snow/ech0","purl":"pkg:golang/github.com/lin-snow/ech0","ranges":["<4.4.3"],"fixed":["4.4.3"]}]},{"id":"GO-2026-5172","url":"https://osv.dev/vulnerability/GO-2026-5172","summary":"Ech0 has Stored XSS via SVG Upload and Content-Type Validation Bypass in File Upload in github.com/lin-snow/ech0","modified":"2026-08-27T04:10:33.767398467Z","packages":[{"ecosystem":"Go","name":"github.com/lin-snow/ech0","purl":"pkg:golang/github.com/lin-snow/ech0","ranges":["all versions"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}