Echo: Encoded slash (%2F) bypasses route-level protection and exposes static files (labstack echo)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.52 % · percentile 44 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Deferred
Description
Echo is a Go web framework. Prior to 4.15.3 and 5.2.0, Echo's router and static file handler disagree on URL path decoding. The router matches routes using the raw encoded path (preserving %2F as-is), while StaticDirectoryHandler unescapes %2F to / before resolving filesystem paths. This allows an attacker to bypass route-level access controls and read static files without authorization. This vulnerability is fixed in 4.15.3 and 5.2.0.
Weaknesses (CWE)
- CWE-22 — Improper Limitation of a Pathname to a Restricted Directory
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | GitHub_M |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-vfp3-v2gw-7wfq — Echo: Encoded slash (%2F) bypasses route-level protection and exposes static files
- GO-2026-6293 — Encoded slash (%2F) bypasses route-level protection and exposes static files in github.com/labstack/echo/v4 and github.com/labstack/echo/v5
European references
- ENISA EUVD · EUVD-2026-39800
- GCVE · GCVE-0-2026-55677
Affected products
| Product | Versions |
|---|---|
| labstack · echo | affected < 4.15.3 ; affected >= 5.0.0, < 5.2.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |