Guzzle is an open source PHP HTTP client. In affected versions the Cookie headers on requests are sensitive information. On making a request using the https scheme to a server which responds with a redirect to a URI with the http scheme, or on making a request to a server which responds with a redirect to a a URI to a different host, we should not forward the Cookie header on. Prior to this fix, only cookies that were managed by our cookie middleware would be safely removed, and any Cookie header manually added to the initial request would not be stripped. We now always strip it, and allow the cookie middleware to re-add any cookies that it deems should be there. Affected Guzzle 7 users should upgrade to Guzzle 7.4.4 as soon as possible. Affected users using any earlier series of Guzzle should upgrade to Guzzle 6.5.7 or 7.4.4. Users unable to upgrade may consider an alternative approach to use your own redirect middleware, rather than ours. If you do not require or expect redirects to be followed, one should simply disable redirects all together.
| Software | From | Fixed in |
|---|---|---|
| guzzlephp / guzzle | 7.0.0 | 7.4.4 |
| guzzlephp / guzzle | - | 6.5.7 |
drupal / drupal
|
9.3.0 | 9.3.16 |
drupal / drupal
|
9.2.0 | 9.2.21 |
drupal / drupal
|
9.4.0-alpha1 | 9.4.0-alpha1.x |
drupal / drupal
|
9.4.0-beta1 | 9.4.0-beta1.x |
drupal / drupal
|
9.4.0-rc1 | 9.4.0-rc1.x |
| debian / debian_linux | 11.0 | 11.0.x |
guzzlehttp / guzzle
|
4.0.0 | 6.5.7 |
guzzlehttp / guzzle
|
7.0.0 | 7.4.4 |
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.