ghsa-4px2-pw77-vc85

{
  "affected": [
    {
      "database_specific": {
        "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-4px2-pw77-vc85/GHSA-4px2-pw77-vc85.json"
      },
      "package": {
        "ecosystem": "SwiftURL",
        "name": "github.com/apple/swift-nio-http2",
        "purl": "pkg:swift/github.com/apple/swift-nio-http2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.44.0"
            }
          ],
          "type": "SEMVER"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-28898"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116",
      "CWE-444"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-12T15:08:16Z",
    "nvd_published_at": "2026-06-25T19:16:36Z",
    "severity": "MODERATE"
  },
  "details": "swift-nio-http2's HTTP/2-to-HTTP/1.1 codec (`HTTP2FramePayloadToHTTP1ServerCodec` / `HTTP2ToHTTP1ServerCodec`) did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message. A remote attacker could send an HTTP/2 request containing CR (\\r), LF (\\n), or NUL (\\0) bytes in pseudo-header values such as `:path`, and when the server translated this to HTTP/1.1 — for example in a reverse-proxy configuration — the resulting output could contain injected headers or entirely smuggled requests.\n\nThis is an HTTP/2-to-HTTP/1.1 request smuggling vulnerability. HTTP/2's binary framing means that CRLF bytes are never parsed as line terminators at the HTTP/2 layer, so they pass through transparently to the HTTP/1.1 output. Any swift-nio-http2 server that translates HTTP/2 requests to HTTP/1.1 and forwards them to a backend is affected. Server-side Swift frameworks such as Vapor that use this codec in a reverse-proxy pattern are directly affected.\n\nThis vulnerability is related to https://github.com/advisories/GHSA-7fj7-39wj-c64f in swift-nio, which addressed CRLF injection in HTTP/1.1 header values but did not cover pseudo-header values in the HTTP/2 layer.\n\nThis vulnerability is also related to https://github.com/advisories/GHSA-cq87-8r7h-962v in swift-nio, which addressed CRLF injection in HTTP/1.1 version, method and path.\n\nswift-nio-http2 1.44.0 adds validation of all pseudo-header values (:path, :authority, :scheme, :method, and :status) at both the HPACK header validation layer and the HTTP/2-to-HTTP/1.1 translation layer. Requests or responses containing CR, LF, or NUL bytes in any pseudo-header value are now rejected with a connection error.\n\nSwiftNIO recommends all adopters upgrade to 1.44.0 as soon as possible.\n\nSwiftNIO thanks @kuranikaran for filing this issue and the support in fixing it.",
  "id": "GHSA-4px2-pw77-vc85",
  "modified": "2026-07-29T05:15:34.230069609Z",
  "published": "2026-06-12T15:08:16Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/apple/swift-nio-http2/security/advisories/GHSA-4px2-pw77-vc85"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-28898"
    },
    {
      "type": "WEB",
      "url": "https://github.com/apple/swift-nio-http2/commit/61d1b44f6e4e118792be1cff88ee2bc0267c6f9a"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/apple/swift-nio-http2"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "SwiftNIO HTTP/2: HTTP/2-to-HTTP/1 Request Smuggling via unvalidated :path pseudo-header in HTTP2ToHTTP1Codec"
}