Description
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.
Published: 2026-06-11
Score: 5.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-34xg-wgjx-8xph guzzlehttp/psr7 has Host Confusion via Authority Reinterpretation
History

Mon, 15 Jun 2026 15:00:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:guzzlephp:psr-7:*:*:*:*:*:*:*:*

Sat, 13 Jun 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1286
References
Metrics threat_severity

None

threat_severity

Moderate


Fri, 12 Jun 2026 20:30:00 +0000

Type Values Removed Values Added
First Time appeared Guzzlephp
Guzzlephp psr-7
Vendors & Products Guzzlephp
Guzzlephp psr-7

Thu, 11 Jun 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 11 Jun 2026 12:45:00 +0000

Type Values Removed Values Added
Description 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.
Title guzzlehttp/psr7 has Host Confusion via Authority Reinterpretation
Weaknesses CWE-20
CWE-918
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-06-11T16:05:56.424Z

Reserved: 2026-05-26T23:26:07.976Z

Link: CVE-2026-48998

cve-icon Vulnrichment

Updated: 2026-06-11T16:05:52.519Z

cve-icon NVD

Status : Analyzed

Published: 2026-06-11T13:16:33.133

Modified: 2026-06-15T14:52:16.857

Link: CVE-2026-48998

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-06-11T12:34:32Z

Links: CVE-2026-48998 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-06-13T02:00:08Z

Weaknesses