Lack of proper header validation for its name and value. The potential attacker can construct deliberately malformed headers with Header class. This could disrupt application functionality, potentially causing errors or generating invalid HTTP requests. In some cases, these malformed requests might lead to a DoS scenario if a remote service’s web application firewall interprets them as malicious and blocks further communication with the application.
Upgrade to v4.5.8 or later.
Validate HTTP header keys and/or values if using user-supplied values before passing them to Header class.
Affected Software:
guzzlehttp/psr7 library.guzzlehttp/psr7 library.Root Cause and Implementation:
guzzlehttp/psr7.Scope of Impact:
guzzlehttp/psr7 library.{
    "nvd_published_at": "2025-01-20T16:15:28Z",
    "github_reviewed_at": "2025-01-21T21:13:40Z",
    "cwe_ids": [
        "CWE-436"
    ],
    "severity": "MODERATE",
    "github_reviewed": true
}