CVE-2026-76139 Red Hat CVE debrief

Who should care

Defenders responsible for Red Hat Advanced Cluster Management for Kubernetes deployments should assess exposure and verify build script integrity. This includes teams managing operator bundles, platform administrators, vulnerability management teams, and security teams responsible for monitoring and responding to potential security incidents. They should review build configurations, ensure secure script execution practices, and monitor for suspicious  

Why it matters

CVE-2026-76139 is a vulnerability in acm-operator-bundle that could allow remote code injection. Defenders should verify build script integrity, ensure secure script download and execution practices, and monitor build environments.

• Verify build script integrity to prevent malicious code injection.
• Ensure secure practices for downloading and executing remote scripts.
• Monitor build environments for suspicious activity.

Technical summary

The acm-operator-bundle component, part of Red Hat Advanced Cluster Management for Kubernetes, downloads and executes a script from a remote source without verifying its authenticity or integrity. This allows a remote attacker to potentially inject malicious code, leading to unauthorized access to build resources. The build process uses full build credentials, which could be exploited if the script is tampered with. Defenders should prioritize verifying the integrity of build scripts and ensuring secure practices for downloading and executing remote scripts. This includes reviewing and updating build configurations to prevent unauthorized script execution and monitoring build environments for suspicious  

Defensive priority

Defenders should prioritize verifying the integrity of build scripts and ensuring secure practices for downloading and executing remote scripts.

Recommended defensive actions

• Review and apply vendor patches or updates for acm-operator-bundle to prevent unauthorized script execution.
• Verify the integrity of build scripts and ensure secure practices for downloading and executing remote scripts.
• Review and update build configurations to prevent unauthorized script execution.
• Monitor build environments for suspicious activity and ensure logging and auditing are in place.
• Perform an inventory of assets using acm-operator-bundle and prioritize patching based on criticality.
• Establish a change management process to track and approve changes to build environments and scripts.
• Track and verify the source of scripts executed during the build process to ensure they have not been tampered with.

Evidence notes

The CVE record and source item provide details about the vulnerability in acm-operator-bundle. Red Hat has provided several errata references (RHSA-2026:60399, RHSA-2026:60400, RHSA-2026:60401, RHSA-2026:60402, RHSA-2026:60403, RHSA-2026:60404) related to this vulnerability.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.