CVE-2025-4600: HTTP Req Smuggling in Google Cloud Classic ALB via Chunked Reqs
CVE-2025-4600 Published on May 16, 2025
HTTP Request Smuggling in Google Cloud Classic Application Load Balancer due to Improper Chunked Encoding Validation
A request smuggling vulnerability existed in the Google Cloud Classic Application Load Balancer due to improper handling of chunked-encoded HTTP requests. This allowed attackers to craft requests that could be misinterpreted by backend servers. The issue was fixed by disallowing stray data after a chunk, and is no longer exploitable. No action is required as Classic Application Load Balancer service after 2025-04-26 is not vulnerable.
Weakness Type
What is a HTTP Request Smuggling Vulnerability?
When malformed or abnormal HTTP requests are interpreted by one or more entities in the data flow between the user and the web server, such as a proxy or firewall, they can be interpreted inconsistently, allowing the attacker to "smuggle" a request to one device without the other device being aware of it.
CVE-2025-4600 has been classified to as a HTTP Request Smuggling vulnerability or weakness.
Products Associated with CVE-2025-4600
Want to know whenever a new CVE is published for Google Application Load Balancer? stack.watch will email you.
Affected Versions
Google Cloud Classic Application Load Balancer Version 0 is affected by CVE-2025-4600Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.