CVE-2026-1727: Agentspace Information Disclosure Flaw

CVE-2026-1727 Overview

The Google Agentspace service was affected by an information exposure vulnerability due to the use of predictable Google Cloud Storage (GCS) bucket names. These bucket names were utilized for error logs and temporary staging during data imports from GCS and Cloud SQL. The predictable naming convention allowed attackers to engage in "bucket squatting" by establishing these buckets before a victim's initial use, potentially capturing sensitive information intended for legitimate service operations.

Critical Impact

Attackers can exploit predictable GCS bucket naming to intercept sensitive error logs and staging data through bucket squatting attacks, leading to unauthorized information disclosure.

Affected Products

• Google Agentspace (versions prior to December 12th, 2025)
• Google Cloud Platform services utilizing Agentspace data import functionality
• Cloud SQL and GCS integration components for Agentspace

Discovery Timeline

• February 6, 2026 - CVE-2026-1727 published to NVD
• February 9, 2026 - Last updated in NVD database

Technical Details for CVE-2026-1727

Vulnerability Analysis

This vulnerability falls under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor). The core issue stems from insufficient randomization in Google Cloud Storage bucket naming conventions used by the Agentspace service. When users import data from GCS or Cloud SQL, the service creates temporary staging buckets and error log buckets following a deterministic naming pattern.

An attacker who understands this naming convention can preemptively create GCS buckets matching the expected names before legitimate users provision their Agentspace instances. When victims subsequently attempt to use Agentspace, the service may inadvertently write sensitive error logs or staging data to attacker-controlled buckets, resulting in unauthorized information disclosure.

The network-accessible nature of this vulnerability means exploitation requires no user interaction and can be performed remotely by any authenticated GCS user capable of creating buckets.

Root Cause

The root cause of this vulnerability is the use of predictable, deterministic naming patterns for Google Cloud Storage buckets used in Agentspace operations. Rather than incorporating sufficient randomization or unique identifiers tied to the customer's infrastructure, the bucket naming scheme followed a pattern that could be anticipated by malicious actors.

This design flaw enabled a classic "bucket squatting" attack vector where adversaries register resources before legitimate users, similar to domain squatting attacks in DNS.

Attack Vector

The attack vector exploits the network-accessible nature of GCS bucket creation combined with predictable naming. An attacker would:

1. Analyze the Agentspace bucket naming convention through documentation, observation, or reverse engineering
2. Pre-create GCS buckets matching anticipated names for target organizations
3. Wait for victims to provision new Agentspace instances or initiate data imports
4. Collect error logs and staging data written to the attacker-controlled buckets

The exploitation mechanism relies on the predictable naming pattern used by Agentspace. When the service attempts to create or access buckets for error logging or data staging operations, it may encounter attacker-controlled buckets matching the expected naming convention. Sensitive information including error logs containing diagnostic data and temporary staging content during GCS and Cloud SQL imports can then be captured by the adversary. For technical implementation details, refer to the Google Cloud Release Notes.

Detection Methods for CVE-2026-1727

Indicators of Compromise

• Unexpected GCS bucket ownership or access denials during Agentspace data import operations
• Error messages indicating bucket already exists when provisioning new Agentspace instances
• Audit logs showing data writes to buckets not owned by the organization
• Failed data import operations with bucket-related error codes

Detection Strategies

• Monitor GCS audit logs for bucket creation failures or unexpected access patterns
• Review Cloud Audit Logs for Agentspace operations that result in permission errors
• Implement alerts for bucket ownership conflicts during service provisioning
• Validate bucket ownership matches expected organizational boundaries before data operations

Monitoring Recommendations

• Enable Data Access audit logs for all GCS operations involving Agentspace
• Configure alerting on bucket creation failures with ALREADY_EXISTS error codes
• Review IAM policies to ensure proper bucket ownership verification
• Monitor for unusual patterns in Agentspace error logging destinations

How to Mitigate CVE-2026-1727

Immediate Actions Required

• Verify that your Agentspace deployment was updated after December 12th, 2025
• Review GCS bucket ownership for any buckets used in Agentspace operations
• Audit Cloud Audit Logs for any suspicious bucket access patterns
• Confirm no unauthorized data was written to unexpected bucket destinations

Patch Information

Google has automatically remediated this vulnerability for all Agentspace deployments. All versions after December 12th, 2025 have been updated to protect from this vulnerability. No user action is required for the patch application itself.

For additional details on the fix, refer to the Google Cloud Release Notes.

Workarounds

• Verify bucket ownership before initiating any Agentspace data import operations
• Pre-create expected GCS buckets with your organization's ownership before using Agentspace features
• Implement strict IAM policies limiting bucket creation and access to authorized principals only
• Use VPC Service Controls to restrict GCS access to trusted perimeters

# Verify Agentspace bucket ownership
gcloud storage buckets describe gs://your-agentspace-bucket --format="json(name,owner)"

# List buckets and check for unexpected ownership
gcloud storage buckets list --filter="name~agentspace" --format="table(name,location,storageClass)"