denied by policy Image was not attested by required attestor on Binary Authorization. what causes it and how to fix

By Sai Kiran Pandrala · Last verified: 2026-05-31 · Source: Google Cloud Community, community Q&A, Google Cloud docs

Running into denied by policy Image was not attested by required attestor on Binary Authorization, what causes it and how to fix on Google Binary Authorization is one of the more searched issues on Google Cloud Community and StackOverflow in the last 12 months. Here is what actually moves the needle when the Google Cloud docs are too generic.

What denied by policy image was not attested by required attestor on binary authorization, what causes it and how to fix actually involves on Google Binary Authorization

The denied by policy Image was not attested by required attestor error from AWS typically surfaces with the message "denied by policy Image was not attested by required attestors". The error code itself is what you grep for in AWS re:Post or in AWS Support cases, not the human-readable line.

On Binary Authorization, this most often comes from one of three causes: a missing or restrictive IAM permission, a service-level limit you have hit, or a transient AWS-side capacity issue. The fix path differs by which.

The rest of this page is the structured fix path. Start with diagnose, then remediation, then the automation options so you do not have to do this by hand the next time it surfaces. Verify and safety sections at the end are the discipline that keeps the fix from regressing in production.

Diagnose first, fix second

Check the Google Cloud Service Health at status.cloud.google.com and the per-product status board for ongoing service events in your region. About one in ten user-reported outages turn out to be region-scoped Google Cloud service degradation already being tracked. Cloud Service Health also exposes an API and Eventarc events, so you can wire a Lambda hook that pages on-call only when the failure correlates with an active Cloud Service Health event in the same region and service.

Run gcloud auth list and gcloud config list first. About one in five 'why does this not work' tickets are actually 'I am in the wrong account' or 'my session expired and the SDK is using stale credentials or ADC pointed at the wrong project'. The 5-second sanity check costs nothing and saves real time when the answer is that simple.

Reproduce the failure with the gcloud CLI in --debug mode. The full SigV4 request payload it emits, plus the exact endpoint URL it resolved to, is what Google Cloud Support uses to verify policy, region, or parameter issues without you having to share IAM credentials. Save the debug output to a file with gcloud ... --debug 2> debug.log and you can search it for the failed aws.request entry.

Solution-focused remediation path

If networking is suspect, use Network Intelligence Connectivity Tests. It is the only tool that simulates the full ENI-to-ENI path including firewall rules, hierarchical firewall policies, routes, and VPC Service Controls perimeters in one call. Manual trace is slower and misses transitive issues. The analyzer charges $0.10 per analysis - cheaper than a 30-minute call with your network team.

If quotas are suspect, the Quotas page in Cloud Console (IAM & Admin > Quotas) console shows current usage and the active limit side by side. Request increases through Quotas page in Cloud Console (IAM & Admin > Quotas), not through Support tickets - quota dashboard requests usually approve faster (often within minutes for soft limits) and they are auditable in Cloud Audit Logs. Set up Quotas page in Cloud Console (IAM & Admin > Quotas) + Cloud Monitoring alert policys at 80 percent usage so you get notified before you hit the wall.

If you cannot reproduce the failure consistently, the cause is probably a race condition or a session-cache issue. Run the call with --profile set to a fresh STS session, in a different region you control, with a single concurrent request. If it works there but fails in your normal setup, the difference is the bug.

Automate this fix so you do not do it twice

Wire the fix into Eventarc for self-healing

If the failure mode is recurring, automate the remediation instead of the diagnosis. Eventarc Scheduler or rules that watch Cloud Logging events for the specific error code can invoke a Lambda that runs the same fix you would run by hand. The Lambda must be idempotent (re-running it on already-healthy resources must be a no-op) and must emit a Cloud Monitoring metric so you can track how often the auto-fix fires. A spike in auto-fix invocations is itself a signal worth alerting on.

# Eventarc rule pattern (JSON)
{ "source": ["aws.google"], "detail-type": ["Google Cloud API Call via Cloud Audit Logs"], "detail": { "errorCode": ["AccessDenied", "ThrottlingException"] }
}

Codify the fix in Terraform or Deployment Manager

When you reach for the console to fix the same issue twice, the third occurrence should be solved in IaC, not in the console. Terraform's terraform import and Deployment Manager or Terraform's resource importer let you adopt the existing resource into state without recreating it. Lock the corrected attribute behind a variable so the next operator does not have to rediscover the value. Add a moved {} block or Deployment Manager or Terraform resource refactor to keep the diff clean.

Add a Cloud Monitoring alert policy so you know next time

The cheapest way to never see the same incident twice is a Cloud Monitoring alert policy on the metric that would have warned you. For Google Binary Authorization, the relevant metrics live under compute.googleapis.com/google namespace or under custom metrics published by your Cloud Run service or GKE pod. Set thresholds based on observed normal range plus one or two standard deviations, not on round-number guesses. Cloud Monitoring anomaly-based alert policies remove the threshold-guessing problem entirely for metrics with regular seasonality.

Common pitfalls and what to watch for

A subtle pitfall on Google Binary Authorization is that the Cloud Console and the SDK can disagree about resource state during a configuration change. Console UI is cached for performance and may show the old config for up to 10 minutes after you change it via API or Deployment Manager or Terraform. Always confirm with describe-* CLI calls during a change window, not with screenshots from the Console.

The other pitfall: assuming that an automated remediation is correct because it succeeded. A Lambda that fires on a Cloud Monitoring alert policy and runs a remediation step should also publish a metric for every remediation; sudden surges in auto-fix invocations are themselves an outage signal. Otherwise you can hide a slow-burn regression behind a quiet remediation loop for weeks.

Verify the fix worked

• Reproduce the original symptom path. If it still surfaces in any account or region or IAM role or service account, you have not fixed it.
• Watch for 24 to 48 hours. Cloud Monitoring metrics and Cloud Asset Inventory can mask issues with cached health for 6 to 12 hours, especially Cloud CDN and Cloud DNS.
• Run a smoke test under realistic load. Happy-path tests miss race conditions and IAM session-cache issues.
• Capture the new state in a runbook so the next person on call does not have to rediscover this. Push it to Confluence or your team wiki, not into Slack.
• If the fix involved a permission change, run IAM Access Analyzer one more time to confirm you did not open a separate hole while closing this one.

Safety, rollback, blast radius

• Test in a non-production account if your environment has Resource Manager and Organization Policy or Cloud Resource Manager (organizations, folders, projects). The cost of one sandbox account is cheaper than one rollback meeting.
• Export the existing config before changing it. Most Google Binary Authorization resources support describe + export to JSON via CLI - capture that to source control before you start.
• Know your rollback path. Some Google Binary Authorization operations are one-way (region migration, account-level feature opt-in, Cloud KMS key deletion past pending window). Confirm reversibility on the Google Cloud doc before you commit.
• Be aware of cross-service impact. IAM role or service account changes ripple to every service trusting that role. Cloud KMS key changes break every workload depending on that key. VPC endpoint changes affect every VPC consumer of that endpoint.
• Maintenance window discipline: if the change touches DNS, certificate rotation, or anything that emits TLS handshakes, line up a window with stakeholder notification, not a heroic mid-day swap.

FAQ

Related fixes

Related guides worth a look while you sort this one out:

• Breakglass annotation to bypass policy in emergency
• Cost included in GKE Cloud Run attestor build cost
• Enable for Cloud Run vs GKE different policy shape
• GKE blocks deploy Revision uses an unauthorized container image
• Multi-project attestor cross-project key access
• PERMISSION_DENIED on Binary Authorization, what causes it and how to fix