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Medium

Fabio - Incomplete fix for CVE-2025-48865: operator-configured trust headers (clientip/tls/requestid) still strippable via the Connection header

Type: advisorySources: OSV

Fabio is an HTTP(S) and TCP router for deploying applications managed by consul. From 1.6.6 until 1.7.2, the CVE-2025-48865 fix in proxy/http_headers.go uses protectHeaders for a hardcoded set of forwarded headers but omits the operator-configured ClientIPHeader, TLSHeader, and RequestID names. In proxy/http_proxy.go, HTTPProxy.ServeHTTP calls addHeaders to set these trust headers before Go ReverseProxy processes the inbound Connection header, allowing an unauthenticated client to name and remove the configured headers before the request reaches the backend. Deployments that enable the corresponding proxy.header options can therefore lose client-IP, TLS-termination, or request-correlation signals used by backend authorization and auditing; the options are empty by default, and the hardcoded protected forwarded headers are unaffected. This issue is fixed in version 1.7.2.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-62987
Confirmed fixed CVEs
Not specified
Updated in this feed
4 Nov 2026, 23:43 UTC · Revision 1

Source evidence

Fabio - Incomplete fix for CVE-2025-48865: operator-configured trust headers (clientip/tls/requestid) still strippable via the Connection header

core-osv · Original source

Published 21 Sept 2026, 16:11 UTC

Fabio is an HTTP(S) and TCP router for deploying applications managed by consul. From 1.6.6 until 1.7.2, the CVE-2025-48865 fix in proxy/http_headers.go uses protectHeaders for a hardcoded set of forwarded headers but omits the operator-configured ClientIPHeader, TLSHeader, and RequestID names. In proxy/http_proxy.go, HTTPProxy.ServeHTTP calls addHeaders to set these trust headers before Go ReverseProxy processes the inbound Connection header, allowing an unauthenticated client to name and remove the configured headers before the request reaches the backend. Deployments that enable the corresponding proxy.header options can therefore lose client-IP, TLS-termination, or request-correlation signals used by backend authorization and auditing; the options are empty by default, and the hardcoded protected forwarded headers are unaffected. This issue is fixed in version 1.7.2.

osv:CVE-2026-62987
Complete source record
{
  "id": "7d1a5df4779c47f3585cefca0c33fb7d0691e76cdd1b53066bb7ce3f43664e75",
  "url": "https://osv.dev/vulnerability/CVE-2026-62987",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Fabio - Incomplete fix for CVE-2025-48865: operator-configured trust headers (clientip/tls/requestid) still strippable via the Connection header",
    "summary": "Fabio is an HTTP(S) and TCP router for deploying applications managed by consul. From 1.6.6 until 1.7.2, the CVE-2025-48865 fix in proxy/http_headers.go uses protectHeaders for a hardcoded set of forwarded headers but omits the operator-configured ClientIPHeader, TLSHeader, and RequestID names. In proxy/http_proxy.go, HTTPProxy.ServeHTTP calls addHeaders to set these trust headers before Go ReverseProxy processes the inbound Connection header, allowing an unauthenticated client to name and remove the configured headers before the request reaches the backend. Deployments that enable the corresponding proxy.header options can therefore lose client-IP, TLS-termination, or request-correlation signals used by backend authorization and auditing; the options are empty by default, and the hardcoded protected forwarded headers are unaffected. This issue is fixed in version 1.7.2.",
    "evidence": "osv:CVE-2026-62987",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-62987",
      "aliases": [
        "CVE-2026-62987",
        "GHSA-fq95-v8xc-jm3v",
        "GO-2026-6566"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/fabiolb/fabio",
              "type": "GIT",
              "events": [
                {
                  "introduced": "945db34c17e87b81f2c5a9160e0b6c5d6f598ce4"
                },
                {
                  "fixed": "602e7e224d98136b5eddbf0d0766fbb59edbdf1a"
                },
                {
                  "fixed": "240526a8004077edad4fb96d25b382bfc3901357"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "1.6.6"
                      },
                      {
                        "fixed": "1.7.2"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "240526a8004077edad4fb96d25b382bfc3901357"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "602e7e224d98136b5eddbf0d0766fbb59edbdf1a"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.7.2"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.7.1",
            "v1.7.0",
            "v1.6.11",
            "v1.6.10",
            "v1.6.9",
            "v1.6.8",
            "v1.6.7",
            "v1.6.6"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-62987.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:40.638230084Z",
      "provider": "osv",
      "references": [
        "https://github.com/fabiolb/fabio/releases/tag/v1.7.2",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/62xxx/CVE-2026-62987.json",
        "https://github.com/fabiolb/fabio/security/advisories/GHSA-fq95-v8xc-jm3v",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-62987",
        "https://github.com/fabiolb/fabio/commit/240526a8004077edad4fb96d25b382bfc3901357"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-290",
          "CWE-348"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/62xxx/CVE-2026-62987.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-62987",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 508086,
  "published_at": "2026-09-21T16:11:21.044+00:00"
}