{"cve":"CVE-2026-25766","nvd":{"published":"2026-02-19T16:27:15.497","modified":"2026-06-17T10:25:11.797","status":"Analyzed","description":"Echo is a Go web framework. In versions 5.0.0 through 5.0.2 on Windows, Echo’s `middleware.Static` using the default filesystem allows path traversal via backslashes, enabling unauthenticated remote file read outside the static root. In `middleware/static.go`, the requested path is unescaped and normalized with `path.Clean` (URL semantics). `path.Clean` does not treat `\\` as a path separator, so `..\\` sequences remain in the cleaned path. The resulting path is then passed to `currentFS.Open(...)`. When the filesystem is left at the default (nil), Echo uses `defaultFS` which calls `os.Open` (`echo.go:792`). On Windows, `os.Open` treats `\\` as a path separator and resolves `..\\`, allowing traversal outside the static root. Version 5.0.3 fixes the issue.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","score":5.3},"cwes":["CWE-22"],"references":["https://github.com/labstack/echo/commit/b1d443086ea27cf51345ec72a71e9b7e9d9ce5f1","https://github.com/labstack/echo/pull/2891","https://github.com/labstack/echo/security/advisories/GHSA-pgvm-wxw2-hrv9"],"products":["labstack:echo"],"source":"nvd","synced_at":"2026-10-19T22:23:35.260773158+00:00"},"epss":{"cve":"CVE-2026-25766","score":0.00382,"percentile":0.32314,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-pgvm-wxw2-hrv9","url":"https://osv.dev/vulnerability/GHSA-pgvm-wxw2-hrv9","summary":"Echo has a Windows path traversal via backslash in middleware.Static default filesystem","modified":"2026-02-27T22:07:05Z","packages":[{"ecosystem":"Go","name":"github.com/labstack/echo/v5","purl":"pkg:golang/github.com/labstack/echo/v5","ranges":[">=5.0.0 <5.0.3"],"fixed":["5.0.3"]}]},{"id":"GO-2026-4502","url":"https://osv.dev/vulnerability/GO-2026-4502","summary":"Echo has a Windows path traversal via backslash in middleware.Static default filesystem in github.com/labstack/echo/v5","modified":"2026-02-26T18:55:57.633080Z","packages":[{"ecosystem":"Go","name":"github.com/labstack/echo/v5","purl":"pkg:golang/github.com/labstack/echo/v5","ranges":[">=5.0.0 <5.0.3"],"fixed":["5.0.3"]}]}],"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."]}