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Medium

guzzlehttp/psr7 has CRLF Injection via URI Host Component

Type: advisorySources: OSV

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 i

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-49214
Confirmed fixed CVEs
Not specified
Updated in this feed
4 Nov 2026, 19:55 UTC · Revision 1

Source evidence

guzzlehttp/psr7 has CRLF Injection via URI Host Component

core-osv · Original source

Published 11 Jun 2026, 12:38 UTC

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 i

osv:CVE-2026-49214
Complete source record
{
  "id": "93ad13e1a5f1178885fece89a74d2167aa53748170df40d87102d03fc6474665",
  "url": "https://osv.dev/vulnerability/CVE-2026-49214",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "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 i",
    "evidence": "osv:CVE-2026-49214",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-49214",
      "aliases": [
        "CVE-2026-49214",
        "GHSA-hq7v-mx3g-29hw"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/guzzle/psr7",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "a1bbdc172f32a25fe999965b65b6e71fd87da9ed"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.10.2"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "cpe": "cpe:2.3:a:guzzlephp:psr-7:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.10.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.10.1",
            "2.10.0",
            "2.9.0",
            "2.8.1",
            "2.8.0",
            "2.7.1",
            "2.7.0",
            "2.6.3",
            "2.6.2",
            "2.6.1",
            "2.6.0",
            "2.5.0",
            "2.4.4",
            "2.4.3",
            "2.4.2",
            "2.4.1",
            "2.4.0",
            "2.3.0",
            "2.2.2",
            "2.2.1",
            "2.2.0",
            "2.1.0",
            "2.0.0",
            "2.0.0-rc1",
            "2.0.0-beta1",
            "1.6.0",
            "1.5.0",
            "1.5.2",
            "1.5.1",
            "1.4.2",
            "1.4.1",
            "1.4.0",
            "1.3.1",
            "1.3.0",
            "1.2.3",
            "1.2.2",
            "1.2.1",
            "1.2.0",
            "1.1.0",
            "1.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49214.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:38.956319251Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49214.json",
        "https://github.com/guzzle/psr7/security/advisories/GHSA-hq7v-mx3g-29hw",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-49214"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-113",
          "CWE-20",
          "CWE-93"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49214.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-49214",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 506409,
  "published_at": "2026-06-11T12:38:22.325+00:00"
}