high7.5
CVE-2026-55677
Echo: Encoded slash (%2F) bypasses route-level protection and exposes static files
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/labstack/echo/v5 | < 5.2.0 | 5.2.0 |
| go | github.com/labstack/echo/v4 | < 4.15.3 | 4.15.3 |
| go | github.com/labstack/echo | <= 3.3.10 | none recorded |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-vfp3-v2gw-7wfq
- https://github.com/labstack/echo/security/advisories/GHSA-vfp3-v2gw-7wfq
- https://nvd.nist.gov/vuln/detail/CVE-2026-55677
- https://github.com/labstack/echo/pull/3009
- https://github.com/labstack/echo/pull/3011
- https://github.com/labstack/echo/commit/8d1ae9d3360a71672418856d58753af25f2c3986
- https://github.com/labstack/echo/commit/c3fa2a27ff92b2b8db360de614f999ef1da24725
- https://github.com/labstack/echo/releases/tag/v4.15.3
- https://github.com/labstack/echo/releases/tag/v5.2.0