Pingora forwards client-nominated Connection headers to HTTP/1 upstreams, allowing ACL bypass in specific chained deployments

{
  "id": "79de119c24c4a33e1fd72a345e7694e15046111b88505b43979fea3f1d8f389d",
  "url": "https://osv.dev/vulnerability/RUSTSEC-2026-0390",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Pingora forwards client-nominated Connection headers to HTTP/1 upstreams, allowing ACL bypass in specific chained deployments",
    "summary": "Pingora versions prior to 0.9.0 passed the downstream request through `upstream_request_filter` and wrote it to HTTP/1 upstreams without removing the client's Connection header, other hop-by-hop headers, or the headers Connection nominated, although RFC 9110 Section 7.6.1 requires intermediaries to remove them. The HTTP/2 upstream path already removed Connection and related HTTP/1-specific headers. A client could therefore nominate a header that the application adds in `upstream_request_filter` (for example, `Connection: keep-alive, X-Forwarded-For`). A downstream HTTP/1 intermediary that honors Connection would then strip the Pingora-added header before it reached the origin. This specifically affects chained deployments where an HTTP/1 intermediary between Pingora and the origin processes Connection nominations (for example, Go's `net/http/httputil.ReverseProxy`) and the origin trusts headers added by that intermediary (for example, X-Forwarded-For for IP-based authorization). A remote, unauthenticated attacker can have those headers removed, potentially bypassing authorization. This is the same class of issue as CVE-2022-31813 in Apache HTTP Server. This flaw was corrected in commits 28c18e6b6b04dd0bd937234e5950049e6d74cded and ca23f1668eca8e78be7ba62ef0edbd458b40eeee. By default, Pingora now removes hop-by-hop and Connection-nominated headers from upstream requests, and rejects requests whose Connection header nominates Host, X-Forwarded-For, X-Forwarded-Host, X-Forwarded",
    "evidence": "osv:RUSTSEC-2026-0390",
    "products": [
      {
        "name": {
          "value": "pingora-proxy",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "0.9.0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "RUSTSEC-2026-0390",
      "aliases": [
        "CVE-2026-105299",
        "GHSA-vx4q-2c55-cvmg",
        "RUSTSEC-2026-0390"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0.0.0-0"
                },
                {
                  "fixed": "0.9.0"
                }
              ]
            }
          ],
          "package": {
            "name": "pingora-proxy",
            "purl": "pkg:cargo/pingora-proxy",
            "ecosystem": "crates.io"
          },
          "database_specific": {
            "cvss": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N",
            "source": "https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0390.json",
            "categories": [],
            "informational": null
          },
          "ecosystem_specific": {
            "affects": {
              "os": [],
              "arch": [],
              "functions": []
            },
            "affected_functions": null
          }
        }
      ],
      "modified": "2026-10-26T11:15:11.361865763Z",
      "provider": "osv",
      "references": [
        "https://crates.io/crates/pingora-proxy",
        "https://rustsec.org/advisories/RUSTSEC-2026-0390.html",
        "https://github.com/cloudflare/pingora/commit/28c18e6b6b04dd0bd937234e5950049e6d74cded",
        "https://github.com/cloudflare/pingora/commit/ca23f1668eca8e78be7ba62ef0edbd458b40eeee"
      ],
      "provider_metadata": {
        "license": "CC0-1.0"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-105299",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 450320,
  "published_at": "2026-10-20T12:00:00+00:00"
}