PT-2026-47222 · Pypi · Psr7

Published

2026-05-29

·

Updated

2026-06-11

·

CVE-2026-48998

CVSS v3.1

5.3

Medium

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Name of the Vulnerable Software and Affected Versions guzzlehttp/psr7 versions prior to 2.10.2
Description Improper Host header validation occurs when parsing raw HTTP request messages or 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 this value is used to construct a URI, it can be reinterpreted as URI userinfo and host, causing the resulting request URI host to differ from the original Host header. This affects applications using the GuzzleHttpPsr7Message::parseRequest() function, the legacy GuzzleHttpPsr7parse request() function, or those building server requests from attacker-controlled server variables that rely on the URI host for routing, allow-list checks, or forwarding. In gateway or forwarding scenarios, this may lead to requests or credentials being sent to an unintended host.
Recommendations Update to version 2.10.2. As a temporary workaround, validate the Host header as uri-host [ ":" port ] before calling Message::parseRequest() or parse request() on untrusted data, or before making routing and forwarding decisions. Reject Host values that contain userinfo, path, query, or fragment delimiters.

Fix

RCE

SSRF

Weakness Enumeration

Related Identifiers

CVE-2026-48998
GHSA-34XG-WGJX-8XPH

Affected Products

Psr7