Agent Development Kit (ADK) - Authentication Bypass (CVE-2026-4810)

CVE-2026-4810 is a critical vulnerability in Google Cloud's Agent Development Kit (ADK) that allows unauthenticated remote attackers to bypass authentication and inject arbitrary code on affected servers. Exploitation of this flaw could lead to full remote code execution, enabling attackers to compromise cloud environments running on Python, Cloud Run, or GKE. This vulnerability poses a significant risk of data theft, service disruption, or further lateral movement within compromised cloud infrastructures.

CrowdSec has been tracking this vulnerability and its exploits since 3rd of June 2026.

CrowdSec network observations suggest that most exploitation of CVE-2026-4810 involves focused reconnaissance to identify viable targets. Attackers typically tailor their campaigns based on system exposure and configuration. It is unlikely that a given attack is accidental. CrowdSec network telemetry also shows that exploitation of CVE-2026-4810 has significantly declined over the past week. Attack volumes are well below the long-term average, suggesting attackers are rapidly losing interest. The vulnerability appears to be falling out of active use across most threat landscapes.

Attackers exploit unauthenticated access to the /builder/save endpoint, uploading malicious Python files to achieve remote code execution on vulnerable Google ADK-Python servers.