Vulnerability-Lookup

GHSA-34XG-WGJX-8XPH

Vulnerability from github – Published: 2026-06-11 13:04 – Updated: 2026-06-12 19:24

Summary

guzzlehttp/psr7 has Host Confusion via Authority Reinterpretation

Details

Impact

guzzlehttp/psr7 improperly interpreted malformed Host header values when constructing request URIs from inbound request data. This issue concerns inbound request parsing and server request construction. It does not require serializing a PSR-7 request, and it is not part of the normal outbound request-sending path used by guzzlehttp/guzzle.

A vulnerable flow is:

An attacker controls a raw HTTP request or server variable containing a Host value.
The Host value contains URI authority delimiters, such as trusted.example@evil.example.
guzzlehttp/psr7 uses that value to construct a URI.
The URI parser treats the portion before @ as userinfo and the portion after @ as the URI host.
The resulting PSR-7 request URI host differs from the original Host header value.

For example, Host: trusted.example@evil.example can result in a PSR-7 URI whose host is evil.example, while the original Host header value remains trusted.example@evil.example.

Applications are affected if they parse attacker-controlled raw HTTP requests with GuzzleHttp\Psr7\Message::parseRequest() or the legacy 1.x GuzzleHttp\Psr7\parse_request() function, or if they build server requests from attacker-controlled server variables with GuzzleHttp\Psr7\ServerRequest::fromGlobals() or GuzzleHttp\Psr7\ServerRequest::getUriFromGlobals(), and then rely on the resulting URI host for routing, allow-list checks, credential selection, or forwarding decisions. Applications using guzzlehttp/psr7 only through Guzzle's standard HTTP client APIs are not expected to be affected. In affected forwarding or gateway scenarios, this may cause requests or credentials to be sent to an unintended host.

Patches

The issue is patched in 2.10.2 and later. 1.x is end-of-life and will not receive a patch.

Workarounds

If you cannot upgrade immediately, validate Host values before passing untrusted request data to Message::parseRequest(), legacy 1.x parse_request(), ServerRequest::fromGlobals(), or ServerRequest::getUriFromGlobals().

Accept only uri-host [ ":" port ]. Reject values containing whitespace, control characters, userinfo (@), path (/ or \), query (?), fragment (#), malformed IP literals or bracket syntax, or invalid port syntax.

Do not validate Host by prefixing it with http:// and passing it to parse_url(), because that can reinterpret malformed values as URI userinfo and host.

References

https://www.rfc-editor.org/rfc/rfc9112.html#section-3.2
https://www.rfc-editor.org/rfc/rfc9112.html#section-3.3
https://www.rfc-editor.org/rfc/rfc9110.html#section-4.2.4
https://www.rfc-editor.org/rfc/rfc9110.html#section-7.2

Severity

5.3 (Medium)


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

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "guzzlehttp/psr7"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.10.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-48998"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-20",
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-11T13:04:53Z",
    "nvd_published_at": "2026-06-11T13:16:33Z",
    "severity": "MODERATE"
  },
  "details": "## Impact\n\n`guzzlehttp/psr7` improperly interpreted malformed `Host` header values when constructing request URIs from inbound request data. This issue concerns inbound request parsing and server request construction. It does not require serializing a PSR-7 request, and it is not part of the normal outbound request-sending path used by `guzzlehttp/guzzle`.\n\nA vulnerable flow is:\n\n1. An attacker controls a raw HTTP request or server variable containing a `Host` value.\n2. The `Host` value contains URI authority delimiters, such as `trusted.example@evil.example`.\n3. `guzzlehttp/psr7` uses that value to construct a URI.\n4. The URI parser treats the portion before `@` as userinfo and the portion after `@` as the URI host.\n5. The resulting PSR-7 request URI host differs from the original `Host` header value.\n\nFor example, `Host: trusted.example@evil.example` can result in a PSR-7 URI whose host is `evil.example`, while the original Host header value remains `trusted.example@evil.example`.\n\nApplications are affected if they parse attacker-controlled raw HTTP requests with `GuzzleHttp\\Psr7\\Message::parseRequest()` or the legacy 1.x `GuzzleHttp\\Psr7\\parse_request()` function, or if they build server requests from attacker-controlled server variables with `GuzzleHttp\\Psr7\\ServerRequest::fromGlobals()` or `GuzzleHttp\\Psr7\\ServerRequest::getUriFromGlobals()`, and then rely on the resulting URI host for routing, allow-list checks, credential selection, or forwarding decisions. Applications using `guzzlehttp/psr7` only through Guzzle\u0027s standard HTTP client APIs are not expected to be affected. In affected forwarding or gateway scenarios, this may cause requests or credentials to be sent to an unintended host.\n\n## Patches\n\nThe issue is patched in `2.10.2` and later. `1.x` is end-of-life and will not receive a patch.\n\n## Workarounds\n\nIf you cannot upgrade immediately, validate Host values before passing untrusted request data to `Message::parseRequest()`, legacy 1.x `parse_request()`, `ServerRequest::fromGlobals()`, or `ServerRequest::getUriFromGlobals()`.\n\nAccept only `uri-host [ \":\" port ]`. Reject values containing whitespace, control characters, userinfo (`@`), path (`/` or `\\`), query (`?`), fragment (`#`), malformed IP literals or bracket syntax, or invalid port syntax.\n\nDo not validate Host by prefixing it with `http://` and passing it to `parse_url()`, because that can reinterpret malformed values as URI userinfo and host.\n\n## References\n\n* https://www.rfc-editor.org/rfc/rfc9112.html#section-3.2\n* https://www.rfc-editor.org/rfc/rfc9112.html#section-3.3\n* https://www.rfc-editor.org/rfc/rfc9110.html#section-4.2.4\n* https://www.rfc-editor.org/rfc/rfc9110.html#section-7.2",
  "id": "GHSA-34xg-wgjx-8xph",
  "modified": "2026-06-12T19:24:02Z",
  "published": "2026-06-11T13:04:53Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/guzzle/psr7/security/advisories/GHSA-34xg-wgjx-8xph"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48998"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/guzzle/psr7"
    }
  ],
  "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": "guzzlehttp/psr7 has Host Confusion via Authority Reinterpretation"
}

CVE-2026-48998 (GCVE-0-2026-48998)

Vulnerability from cvelistv5 – Published: 2026-06-11 12:34 – Updated: 2026-06-11 16:05

Title

guzzlehttp/psr7 has Host Confusion via Authority Reinterpretation

Summary

guzzlehttp/psr7 is a PSR-7 HTTP message library implementation in PHP. Versions prior to 2.10.2 contain improper Host header validation when parsing raw HTTP request messages and when deriving a server request URI from server variables. An attacker can provide a malformed Host header containing URI authority delimiters, such as `trusted.example@evil.example`. When the Host value is used to construct a URI, the malformed value can be reinterpreted as URI userinfo and host. This can cause the PSR-7 request URI host to differ from the original Host header value. Applications are affected if they parse attacker-controlled raw HTTP requests with `GuzzleHttp\Psr7\Message::parseRequest()` or the legacy 1.x `GuzzleHttp\Psr7\parse_request()` function, or if they build server requests from attacker-controlled server variables, then rely on the resulting URI host for routing, allow-list checks, or forwarding decisions. In affected forwarding or gateway scenarios, this may cause requests or credentials to be sent to an unintended host. The issue is patched in `2.10.2`. `1.x` is end-of-life and will not receive a patch. Some workarounds are available. Validate the `Host` header as `uri-host [ ":" port ]` before calling `Message::parseRequest()` or legacy `parse_request()` on untrusted HTTP request data, or before deriving routing and forwarding decisions from a parsed request URI. Reject Host values containing userinfo, path, query, or fragment delimiters.

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 (v2.0.3)

CWE

CWE-20 - Improper Input Validation
CWE-918 - Server-Side Request Forgery (SSRF)

Assigner

GitHub_M

References

1 reference

URL	Tags
https://github.com/guzzle/psr7/security/advisorie…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
guzzle	psr7	Affected: < 2.10.2

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-48998",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-11T16:05:39.189615Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-11T16:05:56.424Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "psr7",
          "vendor": "guzzle",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.10.2"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "guzzlehttp/psr7 is a PSR-7 HTTP message library implementation in PHP. Versions prior to 2.10.2 contain improper Host header validation when parsing raw HTTP request messages and when deriving a server request URI from server variables. An attacker can provide a malformed Host header containing URI authority delimiters, such as `trusted.example@evil.example`. When the Host value is used to construct a URI, the malformed value can be reinterpreted as URI userinfo and host. This can cause the PSR-7 request URI host to differ from the original Host header value. Applications are affected if they parse attacker-controlled raw HTTP requests with `GuzzleHttp\\Psr7\\Message::parseRequest()` or the legacy 1.x `GuzzleHttp\\Psr7\\parse_request()` function, or if they build server requests from attacker-controlled server variables, then rely on the resulting URI host for routing, allow-list checks, or forwarding decisions. In affected forwarding or gateway scenarios, this may cause requests or credentials to be sent to an unintended host. The issue is patched in `2.10.2`. `1.x` is end-of-life and will not receive a patch. Some workarounds are available. Validate the `Host` header as `uri-host [ \":\" port ]` before calling `Message::parseRequest()` or legacy `parse_request()` on untrusted HTTP request data, or before deriving routing and forwarding decisions from a parsed request URI. Reject Host values containing userinfo, path, query, or fragment delimiters."
        }
      ],
      "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"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-20",
              "description": "CWE-20: Improper Input Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-918",
              "description": "CWE-918: Server-Side Request Forgery (SSRF)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-11T12:34:32.397Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/guzzle/psr7/security/advisories/GHSA-34xg-wgjx-8xph",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/guzzle/psr7/security/advisories/GHSA-34xg-wgjx-8xph"
        }
      ],
      "source": {
        "advisory": "GHSA-34xg-wgjx-8xph",
        "discovery": "UNKNOWN"
      },
      "title": "guzzlehttp/psr7 has Host Confusion via Authority Reinterpretation"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-48998",
    "datePublished": "2026-06-11T12:34:32.397Z",
    "dateReserved": "2026-05-26T23:26:07.976Z",
    "dateUpdated": "2026-06-11T16:05:56.424Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-34XG-WGJX-8XPH

Impact

Patches

Workarounds

References

CVE-2026-48998 (GCVE-0-2026-48998)

Tags

Sightings

Nomenclature