# CVE-2026-118653: Echo: Rate Limiter Bypass via Spoofed X-Forwarded-For Header in Default Configuration

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

Echo is a Go web framework. From 4.0.0 until 5.1.0, Context.RealIP falls back to client-supplied X-Forwarded-For or X-Real-IP values when Echo.IPExtractor is unset, and the default RateLimiter uses that result as its client identifier. A remote attacker can rotate arbitrary forwarded-address values to obtain new rate-limit buckets and bypass IP-based throttling used for controls such as brute-force or request-volume protection. This issue is fixed in Echo v5.1.0.

## Remediation

- fix: github.com/labstack/echo/v5 (Go): OSV reports a fixed version 5.1.0. Check the advisory for supported release branches. (source: OSV GHSA-246p-cpwv-v3jq) — https://github.com/advisories/GHSA-246p-cpwv-v3jq

## Affected products and versions

- labstack / echo: >= 4.0.0, < 5.1.0 (affected). Source: CNA: GitHub_M
-  / github.com/labstack/echo/v5 (github.com/labstack/echo/v5): ≥ 0; < 5.1.0 (affected, semver); OSV events: introduced 0; fixed 5.1.0. Source: OSV GHSA-246p-cpwv-v3jq
-  / github.com/labstack/echo/v4 (github.com/labstack/echo/v4): ≥ 4.0.0; ≤ 4.16.2 (affected, semver); OSV events: introduced 4.0.0; last affected 4.16.2. Source: OSV GHSA-246p-cpwv-v3jq

## Severity and prioritization

- CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: 0.41% as of 2026-11-02; percentile 35.83%

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

- Weaknesses: CWE-290

## Exploit evidence

- exploit: https://github.com/labstack/echo/security/advisories/GHSA-246p-cpwv-v3jq (ADP: CISA-ADP)

## References

- https://github.com/labstack/echo/security/advisories/GHSA-246p-cpwv-v3jq (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/labstack/echo/commit/22e4b71109ef072ef011a489066ec662ca9565b2 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/releases/tag/v5.1.0 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/security/advisories/GHSA-246p-cpwv-v3jq (ADP: CISA-ADP; exploit)

- https://github.com/advisories/GHSA-246p-cpwv-v3jq (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-246p-cpwv-v3jq (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-118653; retrieved 2026-11-02; source updated 2026-11-02

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-246p-cpwv-v3jq; retrieved 2026-11-02; source updated 2026-10-28

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-118653; retrieved 2026-11-02; source updated Not reported

Revision: b63354213bb602d1de0aecf8a0855f22ad273f1487beb01f54952e7df727f9d3

Canonical: https://y2.dev/cve/CVE-2026-118653

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