What’s Vulnerable › Vulnerabilities
CVE-2025-4600: HTTP Request Smuggling in Google Cloud Classic Application Load Balancer due to Improper Chunked Encoding Validation
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2025-05-16 · updated 2026-06-17
- Weakness: CWE-444
Description
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.
Affected products
- Google Cloud Classic Application Load Balancer: before 2025-04-26 — fixed in 2025-04-26
How to fix
Upgrade to a fixed version: Google Cloud Classic Application Load Balancer 2025-04-26. Check the vendor advisory for mitigations.
References
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