External risk intelligence

Google Cloud Build Incorrect Authorization Vulnerability Allows Remote Code Execution

CVE advisorySeverity: CRITICAL (CVSS 9.4)

CVE-2026-19410

The vulnerability exists within internal build automation workflows and CI/CD pipeline triggers (GitHub webhook processing). These build environments are typically isolated from the public internet and intended for developer and system-level operations rather than public-facing service exposure.

Halo Surface Signal: 1 out of 5 — much less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A vulnerability in Google Cloud Build's GitHub Trigger Comment Control allowed for unreviewed code execution in build environments via webhook suppression, prior to a patch on June 24, 2026. This issue primarily affects internal development and automation workflows.

Unreviewed code could run in build environments.
Understand if internal development processes were at risk.
Confirm relevance and exposure within our cloud build system.

Attack Path

How an attacker could exploit the issue

An attacker with low-level access could exploit this vulnerability by bypassing security checks related to code review through a specially crafted webhook. This could allow them to execute unreviewed code within the build environment, potentially leading to broader system compromise.

Entry condition: Low-level access required.
Trigger point: Webhook suppression bypass.
Resulting risk: Unreviewed code execution.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an attacker to bypass review processes and execute unverified code within a Google Cloud Build environment, potentially impacting the integrity of build processes when webhook suppression is used.

Build environment code execution.
Webhook suppression exploitation.
Compromised build integrity.

Operational Fix

Recommended remediation, mitigation, and detection steps

While the vulnerability has been patched, understanding potential exposure is crucial for systems that may have used the affected GitHub Trigger Comment Control. Platform or Cloud Infrastructure teams would typically own the Google Cloud Build environment. The first practical step for any organization is to confirm if this specific functionality was in use and assess any historical impact.

Platform/Cloud Infrastructure teams own resolution.
Verify usage of affected GitHub trigger.
Confirm patch status or implement controls.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is Google Cloud Build?

Google Cloud Build is a managed service on the Google Cloud Platform that automates the software development lifecycle. Developers use it to create continuous integration and delivery (CI/CD) pipelines, which automatically build, test, and deploy applications whenever code changes are pushed to a repository, such as GitHub.

What does CWE-345 and CWE-367 mean for CVE-2026-19410?

These codes identify specific software weaknesses. CWE-345 refers to insufficient verification of data authenticity, meaning the system did not properly confirm the source of a request. CWE-367 relates to a time-of-check to time-of-use race condition. Together, they signify that the system failed to securely validate GitHub webhook events, allowing an attacker to bypass authorization and influence the build process.

How is the CVE-2026-19410 vulnerability triggered?

An attacker triggers this by sending a specially crafted webhook to the GitHub Trigger Comment Control component. This bypasses expected review steps by suppressing legitimate security checks. Simply interacting with the build system or commenting on a repository does not trigger the bug; the attacker must specifically target the webhook suppression mechanism to force the execution of unreviewed code.

Is my environment at risk from CVE-2026-19410?

Halo Surface Signal indicates that this vulnerability is very unlikely to be reachable from the public internet. Because the flaw resides within internal CI/CD pipeline triggers and build automation workflows, it typically affects isolated systems rather than public-facing services. You should consider your risk low if your build environments are restricted to internal developer and system-level operations.

Do I need to take action for CVE-2026-19410?

No customer action is required. Google patched this vulnerability in Google Cloud Build on June 24, 2026. If you are responsible for maintaining build pipelines, your first step is to verify that your organization is using the updated version of the service. You may also review historical logs if you suspect your automated build processes were subjected to unauthorized webhook activity prior to the patch date.

References

docs.cloud.google.com/build/docs/release-notes

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.