Fortinet Responds to FortiBleed Campaign

Summary

Fortinet is responding to the FortiBleed campaign, a large-scale credential-harvesting operation that has compiled a database of over 86,000 working credentials for Fortinet devices. The company states this campaign does not exploit new vulnerabilities but rather reuses credentials from previous incidents and employs brute-force techniques against devices with weak passwords and no MFA. Fortinet is notifying impacted customers and working with law enforcement.

Full text

Fortinet says the large-scale credential-harvesting campaign currently targeting its customers’ firewalls and VPNs does not exploit new vulnerabilities. As part of the campaign, tracked as FortiBleed, threat actors have compiled a database of over 86,000 confirmed working credentials for Fortinet devices in 194 countries. “Based on our initial analysis, we believe the activity involves threat actors reusing credentials from previous incidents and employing brute-force techniques against devices with weak password hygiene and no multi-factor authentication (MFA),” the company says. The prior incidents Fortinet refers to involved the exploitation of three FortiCloud SSO login authentication bypass security defects: CVE-2026-24858, patched in January, and CVE-2025-59718 and CVE-2025-59719, addressed in December. “Fortinet provided detailed guidance at the time of these advisories, and we continue to strongly encourage all customers to ensure these remediation steps have been completed,” the company notes. In March, the vendor warned of threat actors’ use of AI to automate target identification and password spraying in large-scale attacks targeting poorly protected edge devices.Advertisement. Scroll to continue reading. FortiBleed, it notes, leverages the same techniques, not a new Fortinet vulnerability. “This activity is not related to any recent incident or advisory,” Fortinet says. The company noted that it has identified the potentially compromised systems, started notifying the impacted customers, and has been working with law enforcement to investigate the attacks. Customers with compromised FortiGate instances are advised to terminate admin and VPN sessions, rotate their credentials, implement MFA on all administrator and VPN user accounts, and upgrade to software releases that support PBKDF2 hashing of administrator credentials. Additionally, they should review firewall and VPN user accounts and configurations for unauthorized changes, check logs for unexpected admin access, and restrict external management to trusted hosts to reduce attack surface. Related: CryptoBandits Malware Doubles as a Backdoor, Abuses Tor Related: Splunk Enterprise Vulnerability Exploited in Attacks Days After Disclosure Related: Critical Vulnerabilities Patched in Fortinet, Ivanti Products Related: Majority of Internet-Accessible REDCap Servers Outdated Written By Ionut Arghire Ionut Arghire is an international correspondent for SecurityWeek. Daily Briefing Newsletter Subscribe to the SecurityWeek Email Briefing for the latest cybersecurity threats, trends, and expert insights. More from Ionut Arghire 15,000 WordPress Websites Cleaned Up in SocGholish Botnet Takedown Majority of Internet-Accessible REDCap Servers OutdatedDream Raises $260 Million at $3 Billion ValuationAtlassian, Splunk Patch Critical VulnerabilitiesCritical Command Execution Vulnerability Patched in Cisco ISEF5 Patches Critical, High-Severity NGINX VulnerabilitiesMicrosoft Teams Relay Servers Abused in DragonForce Ransomware AttackMicrosoft Working on Patch for ‘RoguePlanet’ Zero-Day Latest News More Cybersecurity Firms Disclose Impact From Klue HackTexas Parks & Wildlife Data Breach Affects 3 Million IndividualsFrench President Urges US to Share Cutting-Edge AI and Democracies to Cooperate on RegulationIn Other News: Apple Patches Beats Eavesdropping Flaw, DOT Closes Delta CrowdStrike Probe, AWS ContinuumCryptoBandits Malware Doubles as a Backdoor, Abuses TorFortiBleed: 86,000 Fortinet Device Credentials CompromisedCybersecurity Firms Impacted by Klue Supply Chain AttackCisco to Acquire WideField Security to Boost Splunk’s Agentic SOC Trending Daily Briefing NewsletterSubscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts. Webinar: How Modern Breaches Bypass MFA and Evade Detection June 17, 2026 Today’s attackers are no longer breaking in — they’re logging in. Join this live webinar as we break down the modern identity attack chain and examine how recent breaches exploited weaknesses in authentication, identity verification, and access management processes. Register Webinar: Modern Exposure Validation in the AI Era June 24, 2026 AI has accelerated both sides of the fight. Adversaries are weaponizing vulnerabilities faster, while defenders are racing to ship detections and configurations. Join this live webinar as we explore how to prove your controls actually hold against new threats, map your security maturity, and unite breach simulation with automated pentesting into a single, coordinated program. Register People on the MoveSolarWinds has appointed Justin Henkel as Chief Information Security Officer.J. Paul Haynes has joined Cinchy as Chief Executive Officer.Hatem Naguib has become Chief Executive Officer at Sysdig.More People On The MoveExpert Insights No Exploits Required Four decades of incident response experience suggest that exploits are often the symptom, not the root cause, of today’s cybersecurity failures. (Tod Beardsley) After AI Reaches Production: 12 Ways Security Teams Can Take Control Security teams need more than visibility into AI applications, they need a repeatable framework for monitoring, investigating, and defending them in production. (Joshua Goldfarb) Everybody Is Vibe Coding But Nobody Told the Security Team AI-driven development is not something organizations can or should block. But it must be governed. (Danelle Au) The Zero-Knowledge Threat Actor and the End of Responsible Disclosure AI can help attackers generate malware, create malicious payloads, bypass simple security checks, and convert vague malicious intent into functional code. (Etay Maor) Raising the Cybersecurity Stakes: Ante up for the Agentic Era CISOs are now facing machine-speed attacks and asking, “How do I agent?” The industry must provide remediation at scale. (Nadir Izrael) Flipboard Reddit Whatsapp Whatsapp Email

Indicators of Compromise

• cve — CVE-2026-24858
• cve — CVE-2025-59718
• cve — CVE-2025-59719

Entities