# CVE-2026-118650: Echo: middleware.Static: `%2F`-encoded path bypasses route/group middleware guarding a statically-served path

Status: published. Published: 2026-10-28. Updated: 2026-11-02.

Echo is a Go web framework. Prior to 4.16.0 and 5.4.0, a globally mounted middleware.Static instance can interpret an encoded request path differently from Echo's router because the router matches the still-encoded path while the static handler uses the decoded URL.Path. The advisory demonstrates an encoded slash resolving to a file under the static root through the global static middleware, but the source is internally inconsistent about whether a route or group guard protects the corresponding literal path in that global-mount configuration. This issue is fixed in 4.16.0 and 5.4.0.

## Remediation

- fix: github.com/labstack/echo/v5 (Go): OSV reports a fixed version 5.4.0. Check the advisory for supported release branches. (source: OSV GHSA-375p-5qhx-8wq4) — https://github.com/advisories/GHSA-375p-5qhx-8wq4
- fix: github.com/labstack/echo/v4 (Go): OSV reports a fixed version 4.16.0. Check the advisory for supported release branches. (source: OSV GHSA-375p-5qhx-8wq4) — https://github.com/advisories/GHSA-375p-5qhx-8wq4

## Affected products and versions

- labstack / echo: >= 5.0.0, < 5.4.0 (affected); < 4.16.0 (affected). Source: CNA: GitHub_M
-  / github.com/labstack/echo/v5 (github.com/labstack/echo/v5): ≥ 0; < 5.4.0 (affected, semver); OSV events: introduced 0; fixed 5.4.0. Source: OSV GHSA-375p-5qhx-8wq4
-  / github.com/labstack/echo/v4 (github.com/labstack/echo/v4): ≥ 0; < 4.16.0 (affected, semver); OSV events: introduced 0; fixed 4.16.0. Source: OSV GHSA-375p-5qhx-8wq4

## Severity and prioritization

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: 0.40% as of 2026-11-02; percentile 33.86%

- SSVC: exploitation poc; automatable yes; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-177, CWE-863

## Exploit evidence

- exploit: https://github.com/labstack/echo/security/advisories/GHSA-375p-5qhx-8wq4 (ADP: CISA-ADP)

## References

- https://github.com/labstack/echo/security/advisories/GHSA-375p-5qhx-8wq4 (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/labstack/echo/commit/b838391e2eade87ae7e5a09d7bb5087bec271ec1 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/commit/fc410094b2f3415cf2bf5204082137b205bfd5af (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/releases/tag/v4.16.0 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/releases/tag/v5.4.0 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/security/advisories/GHSA-375p-5qhx-8wq4 (ADP: CISA-ADP; exploit)

- https://github.com/advisories/GHSA-375p-5qhx-8wq4 (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-375p-5qhx-8wq4 (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-118650; retrieved 2026-11-02; source updated 2026-11-02

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-375p-5qhx-8wq4; retrieved 2026-11-02; source updated 2026-10-28

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-118650; retrieved 2026-11-02; source updated Not reported

Revision: a0aa81af054c5f4cfc99bd1a00a97a67130f502981f71bb67a093e15a7f4d8bb

Canonical: https://y2.dev/cve/CVE-2026-118650

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