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Medium

go-chi chi before 5.5.0 Authentication Bypass via SupressNotFound Middleware

Type: advisorySources: Official CVE List

go-chi chi before 5.5.0 contains an authentication bypass in middleware.SupressNotFound, which calls Match with the live routing context and leaves a mounted router's parameter and child suffix in place for dispatch against the outer router. Unauthenticated attackers can request a mounted path whose suffix matches an outer public route, skipping the mounted authentication middleware and retrieving tenant-scoped data when that outer handler trusts the retained mount parameter.

Products
chi
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-118681
Confirmed fixed CVEs
Not specified
Updated in this feed
2 Nov 2026, 02:41 UTC · Revision 1

Source evidence

go-chi chi before 5.5.0 Authentication Bypass via SupressNotFound Middleware

core-cve · Original source

Published 28 Oct 2026, 18:59 UTC

go-chi chi before 5.5.0 contains an authentication bypass in middleware.SupressNotFound, which calls Match with the live routing context and leaves a mounted router's parameter and child suffix in place for dispatch against the outer router. Unauthenticated attackers can request a mounted path whose suffix matches an outer public route, skipping the mounted authentication middleware and retrieving tenant-scoped data when that outer handler trusts the retained mount parameter.

cve:CVE-2026-118681

chi

Fixed versions: Not specified

Complete source record
{
  "id": "acdf55d2a25de7982d4458649d03515d2a44faeca187bb56e096881cbe7d4535",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-118681",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "go-chi chi before 5.5.0 Authentication Bypass via SupressNotFound Middleware",
    "summary": "go-chi chi before 5.5.0 contains an authentication bypass in middleware.SupressNotFound, which calls Match with the live routing context and leaves a mounted router's parameter and child suffix in place for dispatch against the outer router. Unauthenticated attackers can request a mounted path whose suffix matches an outer public route, skipping the mounted authentication middleware and retrieving tenant-scoped data when that outer handler trusts the retained mount parameter.",
    "evidence": "cve:CVE-2026-118681",
    "products": [
      {
        "name": {
          "value": "chi",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-118681",
      "aliases": [
        "CVE-2026-118681"
      ],
      "metrics": [
        {
          "format": "CVSS",
          "cvssV4_0": {
            "version": "4.0",
            "baseScore": 6.3,
            "attackVector": "NETWORK",
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
            "userInteraction": "NONE",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "privilegesRequired": "NONE",
            "subIntegrityImpact": "NONE",
            "vulnIntegrityImpact": "NONE",
            "subAvailabilityImpact": "NONE",
            "vulnAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW"
          }
        },
        {
          "format": "CVSS",
          "cvssV3_1": {
            "scope": "UNCHANGED",
            "version": "3.1",
            "baseScore": 3.7,
            "attackVector": "NETWORK",
            "baseSeverity": "LOW",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
            "integrityImpact": "NONE",
            "userInteraction": "NONE",
            "attackComplexity": "HIGH",
            "availabilityImpact": "NONE",
            "privilegesRequired": "NONE",
            "confidentialityImpact": "LOW"
          }
        }
      ],
      "affected": [
        {
          "vendor": "go-chi",
          "product": "chi",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "5.5.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.5.0",
              "versionType": "semver"
            }
          ],
          "packageURL": "pkg:golang/github.com/go-chi/chi/v5",
          "defaultStatus": "unaffected"
        }
      ],
      "modified": "2026-10-28T18:59:52.523Z",
      "provider": "cve",
      "references": [
        "https://github.com/go-chi/chi/security/advisories/GHSA-rqrp-8cg2-5958",
        "https://www.vulncheck.com/advisories/go-chi-chi-before-5.5.0-authentication-bypass-via-supressnotfound-middleware"
      ],
      "provider_metadata": {
        "cna": {
          "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
          "shortName": "VulnCheck",
          "dateUpdated": "2026-10-28T18:59:52.523Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-118681",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 477117,
  "published_at": "2026-10-28T18:59:52.523+00:00"
}