Executive Summary
In March 2026, attackers exploited a misconfiguration in the aquasecurity/trivy-action GitHub Action, leading to the exfiltration of organization and repository secrets. These credentials were subsequently used to backdoor LiteLLM on PyPI. The static analyzer zizmor is designed to detect such misconfigurations in GitHub Actions workflows. However, with GitHub Actions' introduction of YAML anchors in September 2025, zizmor faced challenges in analyzing workflows utilizing this feature. Over a three-month collaboration, Trail of Bits and zizmor maintainers enhanced zizmor's support for YAML anchors, addressing parsing bugs and improving its expression evaluator. This effort involved testing against a corpus of 41,253 workflows from 6,612 high-value open-source repositories, resulting in 20 filed issues and 15 merged pull requests. The enhancements ensure zizmor can more effectively identify and prevent misconfigurations in GitHub Actions workflows, bolstering the security of CI/CD pipelines. This incident underscores the critical importance of securing CI/CD pipelines against supply chain attacks. As attackers increasingly target CI/CD automation, tools like zizmor play a vital role in identifying and mitigating vulnerabilities before they can be exploited. The collaboration between Trail of Bits and zizmor highlights the necessity of continuous improvement and vigilance in the face of evolving threats.
Why This Matters Now
The recent exploitation of GitHub Actions workflows highlights the urgent need for robust security measures in CI/CD pipelines. As supply chain attacks become more sophisticated, enhancing tools like zizmor is crucial to detect and prevent misconfigurations that could lead to significant breaches.
Attack Path Analysis
Attackers exploited a misconfigured GitHub Action to exfiltrate repository secrets, enabling them to publish backdoored versions of the LiteLLM package on PyPI. These versions harvested sensitive credentials and established persistent access, facilitating lateral movement across Kubernetes clusters. The attackers maintained command and control through encrypted channels, exfiltrated harvested data, and impacted numerous systems by deploying malicious code.
Kill Chain Progression
Initial Compromise
Description
Attackers exploited a misconfigured `pull_request_target` in the `aquasecurity/trivy-action` GitHub Action to exfiltrate repository secrets.
Related CVEs
CVE-2026-33634
CVSS 8.8A supply chain attack on the aquasecurity/trivy-action GitHub Action allowed attackers to exfiltrate organization and repository secrets, leading to the backdooring of LiteLLM on PyPI.
Affected Products:
Aqua Security Trivy Action – 0.0.1, 0.34.2
Exploit Status:
exploited in the wild
MITRE ATT&CK® Techniques
Credentials in Files
Exfiltration to Code Repository
Poisoned Pipeline Execution
Cloud Storage Object
Potential Compliance Exposure
Mapping incident impact across multiple compliance frameworks.
PCI DSS 4.0 – Secure Software Development
Control ID: 6.4.1
NYDFS 23 NYCRR 500 – Cybersecurity Policy
Control ID: 500.03
DORA – ICT Risk Management Framework
Control ID: Article 6
CISA ZTMM 2.0 – Identity and Access Management
Control ID: 3.1
NIS2 Directive – Cybersecurity Risk Management Measures
Control ID: Article 21
Sector Implications
Industry-specific impact of the vulnerabilities, including operational, regulatory, and cloud security risks.
Computer Software/Engineering
Critical exposure to supply-chain attacks through GitHub Actions misconfigurations enabling secret exfiltration and PyPI package backdooring in development workflows.
Information Technology/IT
High risk from automated CI/CD pipeline vulnerabilities allowing lateral movement and data exfiltration through compromised authentication credentials and deployment systems.
Financial Services
Significant threat from supply-chain compromises affecting software dependencies with potential for unauthorized access to sensitive financial data and systems.
Health Care / Life Sciences
Elevated risk from third-party software vulnerabilities potentially compromising HIPAA compliance and patient data through contaminated development tool chains.
Sources
- We hardened zizmor's GitHub Actions static analyzerhttps://blog.trailofbits.com/2026/05/22/we-hardened-zizmors-github-actions-static-analyzer/Verified
- LiteLLM infected with credential-stealing code via Trivyhttps://www.theregister.com/2026/03/24/trivy_compromise_litellm/Verified
- Trojanization of Trivy, Checkmarx, and LiteLLM solutionshttps://www.kaspersky.com/blog/critical-supply-chain-attack-trivy-litellm-checkmarx-teampcp/55510/Verified
Frequently Asked Questions
Cloud Native Security Fabric Mitigations and ControlsCNSF
Aviatrix Zero Trust CNSF is pertinent to this incident as it could have constrained the attacker's ability to exploit misconfigurations, limit lateral movement, and control data exfiltration paths, thereby reducing the overall blast radius.
Control: Cloud Native Security Fabric (CNSF)
Mitigation: The attacker's ability to exploit misconfigured GitHub Actions may have been constrained, reducing the likelihood of unauthorized access to repository secrets.
Control: Zero Trust Segmentation
Mitigation: The attacker's ability to escalate privileges by publishing malicious packages could have been limited, reducing the risk of compromised software distribution.
Control: East-West Traffic Security
Mitigation: The attacker's lateral movement across Kubernetes clusters could have been constrained, reducing the scope of the intrusion.
Control: Multicloud Visibility & Control
Mitigation: The attacker's ability to maintain command and control over compromised systems could have been limited, reducing the duration and impact of the intrusion.
Control: Egress Security & Policy Enforcement
Mitigation: The attacker's ability to exfiltrate sensitive data to external servers could have been constrained, reducing the risk of data loss.
The overall impact of the attack could have been reduced, limiting the extent of data breaches and system compromises.
Impact at a Glance
Affected Business Functions
- Software Development
- Continuous Integration/Continuous Deployment (CI/CD)
Estimated downtime: 3 days
Estimated loss: $50,000
Exfiltration of organization and repository secrets, including PyPI publishing credentials.
Recommended Actions
Key Takeaways & Next Steps
- • Implement Zero Trust Segmentation to restrict lateral movement within Kubernetes clusters.
- • Enforce Egress Security & Policy Enforcement to monitor and control outbound traffic, preventing unauthorized data exfiltration.
- • Utilize Threat Detection & Anomaly Response systems to identify and respond to malicious activities promptly.
- • Apply Inline IPS (Suricata) to detect and prevent known exploit patterns and malicious payloads.
- • Regularly audit and update CI/CD pipelines to identify and remediate misconfigurations that could be exploited.



