Vulnerability-Lookup

GHSA-4PX2-PW77-VC85

Vulnerability from github – Published: 2026-06-12 15:08 – Updated: 2026-07-15 21:23

Summary

SwiftNIO HTTP/2: HTTP/2-to-HTTP/1 Request Smuggling via unvalidated :path pseudo-header in HTTP2ToHTTP1Codec

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.

This 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.

This 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.

This 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.

swift-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.

SwiftNIO recommends all adopters upgrade to 1.44.0 as soon as possible.

SwiftNIO thanks @kuranikaran for filing this issue and the support in fixing it.

Severity

5.3 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

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JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "SwiftURL",
        "name": "github.com/apple/swift-nio-http2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.44.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "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\u0027s 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 \u2014 for example in a reverse-proxy configuration \u2014 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\u0027s 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": "2026-07-15T21:23:10Z",
  "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": "1.4.0",
  "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"
}

CVE-2026-28898 (GCVE-0-2026-28898)

Vulnerability from cvelistv5 – Published: 2026-06-25 18:36 – Updated: 2026-06-25 19:28

Summary

swift-nio-http2's HTTP/2-to-HTTP/1.1 codec did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message. swift-nio-http2 1.44.1 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. This issue is fixed in swift-nio-http2 1.44.1.

Severity

5.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-25 19:28 UTC

CWE

swift-nio-http2's HTTP/2-to-HTTP/1.1 codec did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message.
CWE-116 - Improper Encoding or Escaping of Output

Assigner

apple mitre root Scorecard

References

1 reference

URL	Tags
https://github.com/advisories/GHSA-4px2-pw77-vc85

Impacted products

1 product

Vendor	Product	Version
Apple	swift-nio-http2	Affected: 0 , < 1.44.1 (custom)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 5.3,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "LOW",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-28898",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-25T19:28:33.856470Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-116",
                "description": "CWE-116 Improper Encoding or Escaping of Output",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-25T19:28:38.970Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "swift-nio-http2",
          "vendor": "Apple",
          "versions": [
            {
              "lessThan": "1.44.1",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "swift-nio-http2\u0027s HTTP/2-to-HTTP/1.1 codec did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message. swift-nio-http2 1.44.1 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. This issue is fixed in swift-nio-http2 1.44.1."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "swift-nio-http2\u0027s HTTP/2-to-HTTP/1.1 codec did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message.",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-25T18:36:54.046Z",
        "orgId": "286789f9-fbc2-4510-9f9a-43facdede74c",
        "shortName": "apple"
      },
      "references": [
        {
          "url": "https://github.com/advisories/GHSA-4px2-pw77-vc85"
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "286789f9-fbc2-4510-9f9a-43facdede74c",
    "assignerShortName": "apple",
    "cveId": "CVE-2026-28898",
    "datePublished": "2026-06-25T18:36:54.046Z",
    "dateReserved": "2026-03-03T16:36:03.983Z",
    "dateUpdated": "2026-06-25T19:28:38.970Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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GHSA-4PX2-PW77-VC85

CVE-2026-28898 (GCVE-0-2026-28898)

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