Vulnerability-Lookup

CVE-2026-49214 (GCVE-0-2026-49214)

Vulnerability from cvelistv5 – Published: 2026-06-11 12:38 – Updated: 2026-06-11 12:47

Title

guzzlehttp/psr7 has CRLF Injection via URI Host Component

Summary

guzzlehttp/psr7 is a PSR-7 HTTP message library implementation in PHP. Versions prior to 2.10.2 did not reject ASCII control characters, whitespace, or DEL in first-party URI host components. A vulnerable flow is: First, an application accepts a user-controlled URL. Second, the URL is used to construct a PSR-7 `Uri` or `Request`. Third, the host component contains CRLF or another header-unsafe character. Fourth, the host is copied into the PSR-7 `Host` header when no explicit `Host` header is provided. Finally, the request is serialized or sent by an HTTP client that does not independently reject the malformed host. In that flow, an attacker can cause the serialized request to contain additional attacker-controlled header lines. For example, a host containing `"\r\nX-Injected: yes"` can cause the generated `Host` header to span multiple HTTP header lines. Applications are affected when they use user-controlled URLs for outbound HTTP requests, URL forwarding, proxying, crawling, webhook delivery, or similar request-dispatch flows. In deployments involving HTTP/1.1 connection reuse, proxies, gateways, or load balancers, this malformed request may also contribute to request smuggling or cache poisoning, depending on how downstream components parse the request. The issue is patched in `2.10.2` and later. `1.x` is end-of-life and will not receive a patch. As a workaround, validate and reject all untrusted URI strings before constructing PSR-7 `Uri` or `Request` instances. Reject input containing ASCII control characters, whitespace, or DEL, including CRLF, tab, space, NUL, or DEL characters. Applications that forward requests should also ensure the final HTTP client or serializer rejects invalid URI and header data before writing requests to the network.

Severity

5.3 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-20 - Improper Input Validation
CWE-93 - Improper Neutralization of CRLF Sequences ('CRLF Injection')
CWE-113 - Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')

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

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                "id": "CVE-2026-49214",
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FKIE_CVE-2026-49214

Vulnerability from fkie_nvd - Published: 2026-06-11 13:16 - Updated: 2026-06-11 15:25

Severity

5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/guzzle/psr7/security/advisories/GHSA-hq7v-mx3g-29hw

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "guzzlehttp/psr7 is a PSR-7 HTTP message library implementation in PHP. Versions prior to 2.10.2 did not reject ASCII control characters, whitespace, or DEL in first-party URI host components. A vulnerable flow is: First, an application accepts a user-controlled URL. Second, the URL is used to construct a PSR-7 `Uri` or `Request`. Third, the host component contains CRLF or another header-unsafe character. Fourth, the host is copied into the PSR-7 `Host` header when no explicit `Host` header is provided. Finally, the request is serialized or sent by an HTTP client that does not independently reject the malformed host. In that flow, an attacker can cause the serialized request to contain additional attacker-controlled header lines. For example, a host containing `\"\\r\\nX-Injected: yes\"` can cause the generated `Host` header to span multiple HTTP header lines. Applications are affected when they use user-controlled URLs for outbound HTTP requests, URL forwarding, proxying, crawling, webhook delivery, or similar request-dispatch flows. In deployments involving HTTP/1.1 connection reuse, proxies, gateways, or load balancers, this malformed request may also contribute to request smuggling or cache poisoning, depending on how downstream components parse the request. The issue is patched in `2.10.2` and later. `1.x` is end-of-life and will not receive a patch. As a workaround, validate and reject all untrusted URI strings before constructing PSR-7 `Uri` or `Request` instances. Reject input containing ASCII control characters, whitespace, or DEL, including CRLF, tab, space, NUL, or DEL characters. Applications that forward requests should also ensure the final HTTP client or serializer rejects invalid URI and header data before writing requests to the network."
    }
  ],
  "id": "CVE-2026-49214",
  "lastModified": "2026-06-11T15:25:07.217",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-06-11T13:16:33.300",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/guzzle/psr7/security/advisories/GHSA-hq7v-mx3g-29hw"
    }
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  "vulnStatus": "Undergoing Analysis",
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          "lang": "en",
          "value": "CWE-20"
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          "value": "CWE-93"
        },
        {
          "lang": "en",
          "value": "CWE-113"
        }
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}

GHSA-HQ7V-MX3G-29HW

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

Summary

guzzlehttp/psr7 has CRLF Injection via URI Host Component

Details

Impact

guzzlehttp/psr7 did not reject ASCII control characters, whitespace, or DEL in first-party URI host components. The issue requires a PSR-7 request to be serialized into a raw HTTP/1.x message, for example with GuzzleHttp\Psr7\Message::toString() or an equivalent custom serializer. Creating a Uri, Request, or other PSR-7 object alone is not sufficient. The malformed host must be copied into the serialized Host header without further validation.

A vulnerable flow is:

An application accepts a user-controlled URL.
The URL is used to construct a PSR-7 Uri or Request.
The host component contains CRLF or another header-unsafe character.
The request is serialized into a raw HTTP/1.x message without an explicit Host header.
The host is copied into the serialized Host header.
The serialized request is written to the network or otherwise processed by software that does not independently reject the malformed host.

In that flow, an attacker can cause the serialized request to contain additional attacker-controlled header lines. For example, a host containing "\r\nX-Injected: yes" can cause the generated Host header to span multiple HTTP header lines.

This is not the normal request-sending path used by guzzlehttp/guzzle. Applications using guzzlehttp/psr7 only through Guzzle's standard HTTP client APIs are not expected to be affected. Applications are most likely to be affected when they manually serialize PSR-7 requests, forward raw HTTP messages, or use custom transports, proxying, crawling, webhook delivery, or similar request-dispatch code that serializes requests without independently validating URI hosts and header data. In deployments involving HTTP/1.1 connection reuse, proxies, gateways, or load balancers, this malformed serialized request may also contribute to request smuggling or cache poisoning, depending on how downstream components parse the request.

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 and reject all untrusted URI strings before constructing PSR-7 Uri or Request instances. Reject input containing ASCII control characters, whitespace, or DEL, including CRLF, tab, space, NUL, or DEL characters:

if (preg_match('/[\x00-\x20\x7F]/', $untrustedUrl)) {
    throw new \InvalidArgumentException('Insecure URL detected');
}

Applications that manually serialize or forward requests should also ensure the final HTTP client, transport, or serializer rejects invalid URI and header data before writing requests to the network.

References

https://www.rfc-editor.org/rfc/rfc9112.html#section-3.2
https://www.rfc-editor.org/rfc/rfc9112.html#section-5
https://www.rfc-editor.org/rfc/rfc9112.html#section-11.2
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:N/I:L/A:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "guzzlehttp/psr7"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.10.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-49214"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113",
      "CWE-20",
      "CWE-93"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-11T13:04:47Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Impact\n\n`guzzlehttp/psr7` did not reject ASCII control characters, whitespace, or DEL in first-party URI host components. The issue requires a PSR-7 request to be serialized into a raw HTTP/1.x message, for example with `GuzzleHttp\\Psr7\\Message::toString()` or an equivalent custom serializer. Creating a `Uri`, `Request`, or other PSR-7 object alone is not sufficient. The malformed host must be copied into the serialized `Host` header without further validation.\n\nA vulnerable flow is:\n\n1. An application accepts a user-controlled URL.\n2. The URL is used to construct a PSR-7 `Uri` or `Request`.\n3. The host component contains CRLF or another header-unsafe character.\n4. The request is serialized into a raw HTTP/1.x message without an explicit `Host` header.\n5. The host is copied into the serialized `Host` header.\n6. The serialized request is written to the network or otherwise processed by software that does not independently reject the malformed host.\n\nIn that flow, an attacker can cause the serialized request to contain additional attacker-controlled header lines. For example, a host containing `\"\\r\\nX-Injected: yes\"` can cause the generated `Host` header to span multiple HTTP header lines.\n\nThis is not the normal request-sending path used by `guzzlehttp/guzzle`. Applications using `guzzlehttp/psr7` only through Guzzle\u0027s standard HTTP client APIs are not expected to be affected. Applications are most likely to be affected when they manually serialize PSR-7 requests, forward raw HTTP messages, or use custom transports, proxying, crawling, webhook delivery, or similar request-dispatch code that serializes requests without independently validating URI hosts and header data. In deployments involving HTTP/1.1 connection reuse, proxies, gateways, or load balancers, this malformed serialized request may also contribute to request smuggling or cache poisoning, depending on how downstream components parse the request.\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 and reject all untrusted URI strings before constructing PSR-7 `Uri` or `Request` instances. Reject input containing ASCII control characters, whitespace, or DEL, including CRLF, tab, space, NUL, or DEL characters:\n\n```php\nif (preg_match(\u0027/[\\x00-\\x20\\x7F]/\u0027, $untrustedUrl)) {\n    throw new \\InvalidArgumentException(\u0027Insecure URL detected\u0027);\n}\n```\n\nApplications that manually serialize or forward requests should also ensure the final HTTP client, transport, or serializer rejects invalid URI and header data before writing requests to the network.\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-5\n* https://www.rfc-editor.org/rfc/rfc9112.html#section-11.2\n* https://www.rfc-editor.org/rfc/rfc9110.html#section-7.2",
  "id": "GHSA-hq7v-mx3g-29hw",
  "modified": "2026-06-11T13:04:47Z",
  "published": "2026-06-11T13:04:47Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/guzzle/psr7/security/advisories/GHSA-hq7v-mx3g-29hw"
    },
    {
      "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:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "guzzlehttp/psr7 has CRLF Injection via URI Host Component"
}

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

CVE-2026-49214 (GCVE-0-2026-49214)

FKIE_CVE-2026-49214

GHSA-HQ7V-MX3G-29HW

Impact

Patches

Workarounds

References

Tags

Sightings

Nomenclature