Pingora HTTP/2 server memory exhaustion through unbounded default header-list and concurrent-stream limits

{
  "id": "07bb6a6b660a22d36627d9202cb111690bbfdd077768d32545105aa51b2ed4d2",
  "url": "https://osv.dev/vulnerability/RUSTSEC-2026-0389",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Pingora HTTP/2 server memory exhaustion through unbounded default header-list and concurrent-stream limits",
    "summary": "Pingora versions prior to 0.8.1 used the h2 crate's default HTTP/2 server limits, a 16 MiB decoded header-list size and no limit on concurrent streams, unless the application set its own. A remote, unauthenticated client can send 1-byte HPACK references to a near-empty header, making the server allocate hundreds of thousands of header fields per stream across an unlimited number of streams on one connection, and use HTTP/2 flow control to keep those streams open. This can exhaust memory and degrade or terminate the Pingora process. This affects any Pingora service that terminates HTTP/2 (h2 or h2c) without explicitly setting `max_header_list_size` and `max_concurrent_streams`. The reporter showed that a single connection could get a Pingora process with a 2 GiB memory limit OOM-killed. This flaw was corrected in commit d193c8d49b8b7c1c1ede93183759caa4f6906bbd. When no `H2Options` are supplied, Pingora now advertises and enforces a 64 KiB decoded header-list limit and at most 100 concurrent streams per connection. Users should upgrade to Pingora >= 0.8.1. Applications that supply their own `H2Options` are not covered by these defaults and must set `max_header_list_size` and `max_concurrent_streams` explicitly, or start from `pingora_core::protocols::http::v2::server::default_h2_options()`. `H2Options::default()` does not include these limits. Note: Cloudflare CDN customers were unaffected, as internal Pingora services at Cloudflare do not have HTTP/2 clients.",
    "evidence": "osv:RUSTSEC-2026-0389",
    "products": [
      {
        "name": {
          "value": "pingora-core",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "0.8.1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "RUSTSEC-2026-0389",
      "aliases": [
        "CVE-2026-105297",
        "GHSA-7gpj-mj4q-x62x",
        "RUSTSEC-2026-0389"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0.0.0-0"
                },
                {
                  "fixed": "0.8.1"
                }
              ]
            }
          ],
          "package": {
            "name": "pingora-core",
            "purl": "pkg:cargo/pingora-core",
            "ecosystem": "crates.io"
          },
          "database_specific": {
            "cvss": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "source": "https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0389.json",
            "categories": [
              "denial-of-service"
            ],
            "informational": null
          },
          "ecosystem_specific": {
            "affects": {
              "os": [],
              "arch": [],
              "functions": []
            },
            "affected_functions": null
          }
        }
      ],
      "modified": "2026-10-26T11:15:11.357540777Z",
      "provider": "osv",
      "references": [
        "https://crates.io/crates/pingora-core",
        "https://rustsec.org/advisories/RUSTSEC-2026-0389.html",
        "https://github.com/cloudflare/pingora/commit/d193c8d49b8b7c1c1ede93183759caa4f6906bbd"
      ],
      "provider_metadata": {
        "license": "CC0-1.0"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-105297",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 450319,
  "published_at": "2026-10-20T12:00:00+00:00"
}