# CVE-2026-118654: Echo static file middleware route protection bypass via encoded dot-dot traversal

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, Echo's static file handlers can normalize dot segments after route matching and serve a file through a public static route even though the corresponding direct path is protected by route-level middleware. An unauthenticated attacker can read files that an application intended to protect with route-level middleware, when those files are also reachable through a static filesystem mount after path normalization. This vulnerability is the result of an incomplete fix for CVE-2026-55677. 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-3pmx-cf9f-34xr) — https://github.com/advisories/GHSA-3pmx-cf9f-34xr
- 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-3pmx-cf9f-34xr) — https://github.com/advisories/GHSA-3pmx-cf9f-34xr

## Affected products and versions

- labstack / echo: < 4.16.0 (affected); >= 5.0.0, < 5.4.0 (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-3pmx-cf9f-34xr
-  / 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-3pmx-cf9f-34xr

## Severity and prioritization

- CVSS 3.1: 5.9 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: 0.35% as of 2026-11-02; percentile 28.26%

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-22

## Exploit evidence

- exploit: https://github.com/labstack/echo/security/advisories/GHSA-3pmx-cf9f-34xr (ADP: CISA-ADP)

## References

- https://github.com/labstack/echo/security/advisories/GHSA-3pmx-cf9f-34xr (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-3pmx-cf9f-34xr (ADP: CISA-ADP; exploit)

- https://github.com/advisories/GHSA-3pmx-cf9f-34xr (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-3pmx-cf9f-34xr (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-118654; retrieved 2026-11-02; source updated 2026-11-02

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-3pmx-cf9f-34xr; retrieved 2026-11-02; source updated 2026-10-28

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-118654; retrieved 2026-11-02; source updated Not reported

Revision: f881a762ab7fc0275de578484c43b02f10c980ebd32891f223c70ff6c28600ac

Canonical: https://y2.dev/cve/CVE-2026-118654

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.