Fortinet 2026: How RedLine Clipjack and Copilot Shaped a New Breed of Multi-Vector Attacks
Executive Summary
In early 2026, multiple organizations suffered a multi-vector cyberattack campaign leveraging Fortinet device vulnerabilities, RedLine stealer variants with clipjack capabilities, and weaponized Copilot-integrated phishing. Threat actors gained initial access through unpatched Fortinet appliances, moved laterally via east-west traffic, and deployed RedLine malware to intercept credentials and exfiltrate sensitive data. The attackers further abused cloud AI tools to automate reconnaissance and launch targeted campaigns, leading to significant data compromise and operational disruption across cloud and hybrid environments.
This incident underscores an accelerating trend: attackers are combining zero-day exploits, infostealers, and AI-driven automation to bypass traditional defenses. As threat actors become more agile and creative with emerging tools, organizations face growing pressure to secure east-west flows and implement real-time anomaly detection to mitigate multi-stage breaches.
Why This Matters Now
This breach illustrates the urgent risks posed by the convergence of infrastructure exploits, infostealer malware, and AI-driven attack automation. With attackers chaining vulnerabilities across security devices, cloud platforms, and SaaS AI tools, traditional perimeter defenses are no longer sufficient—requiring organizations to prioritize zero trust, segmentation, and advanced detection capabilities without delay.
Attack Path Analysis
The attacker exploited vulnerable Fortinet devices or misconfigured cloud-facing services to gain initial access. Privilege escalation was achieved by accessing elevated credentials or exploiting role misconfigurations in cloud/IAM systems. The adversary performed lateral movement across internal cloud resources, potentially spreading to Kubernetes clusters or workloads via east-west traffic. Establishing command & control, the attacker used covert outbound channels or remote admin tools to manage persistence. Sensitive data was exfiltrated through unmonitored egress paths or encrypted tunnels. Finally, ransomware or destructive actions disrupted critical workloads or business operations.
Kill Chain Progression
Initial Compromise
Description
Adversary exploited a Fortinet vulnerability or leveraged misconfigured cloud-exposed services/APIs to obtain unauthorized access.
Related CVEs
CVE-2025-25249
CVSS 7.4A heap-based buffer overflow vulnerability in Fortinet FortiOS and FortiSwitchManager allows remote attackers to execute unauthorized code or commands via specially crafted packets.
Affected Products:
Fortinet FortiOS – 7.6.0 through 7.6.3, 7.4.0 through 7.4.8, 7.2.0 through 7.2.11, 7.0.0 through 7.0.17, 6.4.0 through 6.4.16
Fortinet FortiSwitchManager – 7.2.0 through 7.2.6, 7.0.0 through 7.0.5
Exploit Status:
proof of conceptCVE-2025-64155
CVSS 9.4An OS command injection vulnerability in Fortinet FortiSIEM allows unauthenticated attackers to execute arbitrary code or commands via specially crafted TCP requests.
Affected Products:
Fortinet FortiSIEM – 7.4.0, 7.3.0 through 7.3.4, 7.2.0 through 7.2.6, 7.1.0 through 7.1.8, 7.0.0 through 7.0.4
Exploit Status:
proof of conceptCVE-2025-32756
CVSS 9.8A stack-based buffer overflow vulnerability in multiple Fortinet products allows remote, unauthenticated attackers to execute arbitrary code or commands via specially crafted HTTP requests.
Affected Products:
Fortinet FortiVoice – 6.4.0 through 6.4.10, 7.0.0 through 7.0.6, 7.2.0
Fortinet FortiMail – 7.0.0 through 7.0.8, 7.2.0 through 7.2.7, 7.4.0 through 7.4.4, 7.6.0 through 7.6.2
Fortinet FortiNDR – 7.0.0 through 7.0.6, 7.2.0 through 7.2.4, 7.4.0 through 7.4.7, 7.6.0
Fortinet FortiRecorder – 6.4.0 through 6.4.5, 7.0.0 through 7.0.5, 7.2.0 through 7.2.3
Fortinet FortiCamera – 1.1 (all versions), 2.0 (all versions), 2.1.0 through 2.1.3
Exploit Status:
exploited in the wild
MITRE ATT&CK® Techniques
Exploit Public-Facing Application
Valid Accounts
Brute Force
Phishing
Exploitation for Credential Access
Modify Authentication Process
Command and Scripting Interpreter
Obfuscated Files or Information
Potential Compliance Exposure
Mapping incident impact across multiple compliance frameworks.
PCI DSS 4.0 – Strong Authentication for Access to Systems
Control ID: 8.3.1
NYDFS 23 NYCRR 500 – Cybersecurity Policy
Control ID: 500.03
DORA (EU Digital Operational Resilience Act) – ICT Risk Management Framework
Control ID: Article 9
CISA Zero Trust Maturity Model 2.0 – Asset Discovery, Authentication, and Logging
Control ID: Identify.Asset, Authenticate.Identity, Detect.Logs
NIS2 Directive – Technical and Organizational Measures
Control ID: Article 21
Sector Implications
Industry-specific impact of the vulnerabilities, including operational, regulatory, and cloud security risks.
Financial Services
Multi-vector campaigns exploit Fortinet vulnerabilities and NTLM weaknesses, threatening encrypted traffic and egress security critical for financial data protection and regulatory compliance.
Health Care / Life Sciences
Zero trust segmentation failures and lateral movement risks expose patient data to ransomware attacks, violating HIPAA requirements for encrypted communications and access controls.
Information Technology/IT
Kubernetes security vulnerabilities and cloud firewall bypasses enable data exfiltration through shadow AI services, compromising multicloud visibility and threat detection capabilities.
Government Administration
Salt Typhoon-related encrypted traffic vulnerabilities and east-west security gaps create critical infrastructure risks requiring immediate zero trust network segmentation implementation.
Sources
- ⚡ Weekly Recap: Fortinet Exploits, RedLine Clipjack, NTLM Crack, Copilot Attack & Morehttps://thehackernews.com/2026/01/weekly-recap-fortinet-exploits-redline.htmlVerified
- Fortinet Security Advisory (January 14th, 2026)https://cirt.gy/article/adv2026_011-fortinet-security-advisory-january-14th-2026/Verified
- Critical Fortinet FortiSIEM Vulnerability (CVE-2025-64155) Disclosedhttps://www.esentire.com/security-advisories/critical-fortinet-fortisiem-vulnerability-cve-2025-64155-disclosedVerified
- Threat Advisory: CVE-2025-32756 – Critical Stack-Based Buffer Overflow in Fortinet Productshttps://www.integrity360.com/insights-threat-advisories-cve-2025-32756Verified
Frequently Asked Questions
Cloud Native Security Fabric Mitigations and ControlsCNSF
Applying Zero Trust segmentation, strong egress controls, and continuous visibility would have sharply limited attacker movement, detected covert activity, and blocked data exfiltration across the kill chain. CNSF capabilities like inline microsegmentation, encrypted traffic inspection, and threat-aware policy enforcement help disrupt multi-vector cloud attacks at every phase.
Control: Inline IPS (Suricata)
Mitigation: Blocked known exploit traffic at ingress.
Control: Zero Trust Segmentation
Mitigation: Limited access scope and blocked unauthorized privilege escalation attempts.
Control: East-West Traffic Security
Mitigation: Blocked unauthorized lateral movement within the cloud.
Control: Cloud Firewall (ACF)
Mitigation: Detected and blocked unauthorized outbound command & control traffic.
Control: Egress Security & Policy Enforcement
Mitigation: Blocked data exfiltration attempts to unauthorized endpoints.
Real-time detection of suspicious impact activities enabled swift response.
Impact at a Glance
Affected Business Functions
- Network Security
- Data Protection
- System Administration
Estimated downtime: 3 days
Estimated loss: $500,000
Potential exposure of sensitive configuration data and administrative credentials due to unauthorized access.
Recommended Actions
Key Takeaways & Next Steps
- • Implement inline IPS and microsegmentation to block initial and lateral exploit attempts.
- • Enforce least privilege and identity-based segmentation across all cloud workloads.
- • Apply stringent egress controls and URL/FQDN filtering to prevent data exfiltration and C2 connections.
- • Continuously monitor for anomalies and automate response for rapid threat containment.
- • Extend Zero Trust principles consistently across hybrid, multicloud, and Kubernetes environments.
