CVE-2025-4600
A request smuggling vulnerability existed in the Google Cloud Classic Application Load Balancer due to improper handling of chunked-encoded HTTP requests.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.20%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.20% probability · 9th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-444
- Affected
- google/application load balancer
- Source
- cve-coordination@google.com
References
- https://cloud.google.com/support/bulletins#gcp-2025-027Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.