Fortinet VPN Alternative 2026: Replace FortiClient with NetBird

Fortinet has a security problem – and now an architecture problem too. Over 16,000 FortiGate devices were compromised via a symlink backdoor that persisted even after patching. At the same time, Fortinet is removing SSL VPN entirely from all FortiGate models starting with FortiOS 7.6.3. Anyone using FortiClient SSL VPN today faces a forced migration – and must ask: is switching to IPsec with all its known risks worth it? Or is now the right time to decouple VPN from the firewall? NetBird offers a modern way out: open-source mesh VPN built on WireGuard, as a managed service hosted in Germany – no appliance, no FortiClient, from €99.90/month.

Also worth reading: Sophos VPN Alternative 2026 · OpenVPN Alternative 2026 · NetBird vs. Tailscale 2026

Quick Comparison: FortiGate VPN vs. NetBird

Table of Contents

• FortiOS 7.6: Fortinet Removes SSL VPN
  • The Timeline
  • What This Means for Businesses
• The Fortinet Security Crisis: CVE Series, Backdoors, and Attacks
  • The Most Critical Vulnerabilities
  • The Symlink Backdoor: 16,000+ Devices Compromised – Even After Patching
  • What the CVE Series Shows
• The Structural Problem: VPN on the Firewall
• The Alternative Approach: Decouple VPN from the Firewall
• Architecture: FortiClient SSL VPN vs. NetBird Mesh VPN
  • FortiClient SSL VPN: How It Works Today
  • NetBird: How the Mesh VPN Works
  • Architecture Comparison
• Security: SSL VPN Vulnerabilities vs. WireGuard
  • Security Comparison
• Setup and Operations: FortiClient Ecosystem vs. Self-Service Portal
  • FortiGate + FortiClient: What Operations Really Cost
  • NetBird: Three Ways to Deploy
  • birdhost: Ready in Minutes
• Cost Comparison
  • 3-Year Cost Comparison for an SMB (20–50 Employees)
  • birdhost Volume Pricing
• GDPR and Compliance
• Migration: From FortiClient SSL VPN to NetBird
• Full Comparison at a Glance
• Decision Guide: When FortiGate, When NetBird?
  • Staying with FortiGate makes sense if you:
  • NetBird / birdhost is the better choice if you:
  • The Combination: FortiGate + NetBird
• Conclusion
• Sources

FortiOS 7.6: Fortinet Removes SSL VPN

Perhaps the most important news for FortiGate admins in 2026: Fortinet is removing SSL VPN tunnel mode entirely.

The Timeline

• FortiOS 7.4.8: SSL VPN removed on devices with 2 GB RAM or less (FortiGate 40F, 60F, 61F, 50G, 70G, 90G)
• FortiOS 7.6.0: SSL VPN no longer accessible via GUI or CLI on 2 GB models
• FortiOS 7.6.3 and higher: SSL VPN tunnel mode unavailable on any FortiGate model – regardless of hardware

This means: anyone using SSL VPN on a FortiGate who plans a firmware upgrade will lose VPN tunnel access. Existing SSL VPN configurations – including firewall policies – are not migrated during upgrade and must be manually converted to IPsec VPN.

What This Means for Businesses

1. Forced migration: Every business using FortiClient SSL VPN must take action. Either migrate to IPsec VPN (with FortiClient as client), switch to FortiSASE (cloud-based, additional costs) – or decouple VPN from the firewall entirely.

2. No replacement for SSL VPN web mode: Fortinet itself confirms there is no direct alternative for SSL VPN web mode (browser-based access without client). Businesses using this mode for contractor access or BYOD face a gap.

3. IPsec isn't simpler: The recommended migration to IPsec VPN requires rebuilding configurations, client updates on all endpoints, and firewall policy adjustments. If you've been using SSL VPN over port 443, you need to verify that IPsec-over-TCP works in your network environment.

4. Entry-level models affected first: The best-selling SMB models – FortiGate 40F and 60F – have only 2 GB RAM and lose SSL VPN already with FortiOS 7.4.8. The very devices most commonly used for remote access VPN.

The Fortinet Security Crisis: CVE Series, Backdoors, and Attacks

With over 50% global market share, Fortinet is the world's most deployed firewall vendor – and consequently the preferred target for attackers. The security track record of the last two years reads like a worst-case scenario.

The Most Critical Vulnerabilities

CVE-2024-47575 – "FortiJump" (CVSS 9.8): Missing authentication in the FortiManager daemon enabled remote code execution without login. The threat group UNC5820 exploited the vulnerability since June 2024 – months before Fortinet released a patch in October 2024. FortiGate configurations and hashed passwords were exfiltrated. Security researchers assessed the initial patch as insufficient.

CVE-2024-55591 – Authentication Bypass (CVSS 9.6): Attackers could gain super-admin privileges via crafted requests to the Node.js websocket module. The vulnerability was actively exploited as a zero-day – targeting publicly exposed FortiGate management interfaces.

CVE-2025-24472 – Authentication Bypass: Closely related to CVE-2024-55591. The ransomware group "Mora_001" – with suspected links to LockBit – exploited both vulnerabilities to gain initial access and escalate to super-admin privileges.

CVE-2024-21762 – Zero-Day in SSL VPN: An out-of-bounds write vulnerability in FortiOS SSL VPN that was, according to Fortinet, "potentially being exploited in the wild." CISA added it to the Known Exploited Vulnerabilities catalog.

CVE-2025-59718 – Authentication Bypass (December 2025): The latest in the series: attackers bypass authentication on FortiGate firewalls and export system configuration files. CISA added the CVE to the KEV catalog.

FortiBleed (June 2026): In June 2026, the credential harvesting campaign known as "FortiBleed" showed just how large the attack surface of exposed FortiGates really is: according to Bitsight, credentials for more than 73,000 FortiGate firewalls and SSL VPN gateways were exposed. On June 18, 2026, CISA urged operators to terminate active sessions, reset credentials, and remove management interfaces from the public internet.

The Symlink Backdoor: 16,000+ Devices Compromised – Even After Patching

In April 2025, Fortinet disclosed a technique that calls into question the security model of every firewall appliance: attackers placed symbolic links in the SSL VPN language file directory pointing to the FortiGate's root filesystem. Because these files aren't overwritten during firmware updates, access persisted even after complete patching.

The facts:

• 16,620 compromised devices according to the Shadowserver Foundation (as of April 2025)
• Attackers had persistent read access to configuration files, certificates, and credentials
• The backdoor survived every firmware update – only targeted cleanup helped
• Geographic distribution: 7,886 devices in Asia, 3,766 in Europe, 3,217 in North America
• Fortinet notified affected customers via email and released AV/IPS signatures for detection

Patch bypass discovered (February 2026): Security researchers found that Fortinet's patch relied on weak string matching. By adding a double slash to the path (/lang//custom instead of /lang/custom), the security check was completely bypassed – while the web server still resolved the path correctly.

What the CVE Series Shows

The problem isn't a single bug – it's a pattern. Fortinet appliances with SSL VPN are reachable from the internet by design. Every vulnerability in this attack vector gives attackers direct access to core infrastructure. And the patch quality – an initial patch that gets bypassed, a second patch that gets bypassed again – undermines trust in the entire ecosystem.

On top of that comes the credential layer, which no patch can undo: in June 2026, Bitsight documented a circulating dataset with administrator and VPN credentials for more than 73,000 internet-facing FortiGate firewalls. We cover what is behind the FortiGate credential leak FortiBleed and which immediate actions matter in a separate analysis.

The Structural Problem: VPN on the Firewall

The CVE series isn't a Fortinet-specific problem – it's an architecture problem. Sophos, WatchGuard, Lancom, and every other vendor bundling VPN on the firewall appliance shares the same attack surface.

The appliance is simultaneously firewall, VPN gateway, and attack target. The SSL VPN portal must be reachable from the internet so remote employees can connect. That very reachability makes the appliance a target – as the Fortinet CVEs have been continuously demonstrating since 2023.

VPN traffic competes with firewall processing. IDS/IPS, application control, TLS inspection, web filtering, and VPN encryption all run on the same hardware. On entry-level models like the FortiGate 40F or 60F, the CPU hits its limit quickly.

Hardware lifecycle forces VPN migrations. When the appliance is replaced after 3–5 years, the entire VPN must be migrated – profiles, certificates, client configurations. Fortinet's decision to remove SSL VPN accelerates this cycle further. How hard such an end of support can hit is currently on display at Cisco: support for the ASA 5506-X, 5508-X, and 5516-X ends on August 31, 2026, with AnyConnect 4.x already out of security patches.

Every vulnerability in the firewall is a VPN vulnerability. And vice versa. The symlink backdoor could only exist because SSL VPN and the filesystem run on the same appliance.

The Alternative Approach: Decouple VPN from the Firewall

The core idea: Your FortiGate stays responsible for perimeter security. VPN is operated as a separate, modern service.

This doesn't mean throwing away your FortiGate. If your FortiGate does good work as a firewall – IDS/IPS, application control, web filtering – keep it. But free it from the VPN load and the associated attack surface.

NetBird handles the VPN part, operated as managed NetBird hosting: encrypted connections between devices, identity-based access control, automatic on-/offboarding. The FortiGate can focus on what it was built for: perimeter protection, traffic inspection, network segmentation.

Bonus: Without an active SSL VPN portal, the attack vector responsible for the entire CVE series of the last two years disappears.

Architecture: FortiClient SSL VPN vs. NetBird Mesh VPN

FortiClient SSL VPN: How It Works Today

Remote Laptop ──► Internet ──► FortiGate (Port 443/10443) ──► LAN
                                 │ Decrypt SSL VPN
                                 │ Check firewall rules
                                 │ Forward traffic

• Client: FortiClient (Windows, macOS, Linux, iOS, Android)
• Authentication: Username + password, optional MFA (FortiToken)
• Management: FortiClient EMS (Endpoint Management Server) – own infrastructure or cloud
• Access control: SSL VPN policy with split tunneling and firewall rules

NetBird: How the Mesh VPN Works

Remote Laptop ◄────── WireGuard Tunnel ──────► Routing Peer (Office)
                   (direct, peer-to-peer)              │
                                                   LAN Devices

• Client: NetBird (Windows, macOS, Linux, iOS, Android – one client for all)
• Authentication: SSO via identity provider (Azure AD, Google Workspace, Okta, Keycloak)
• Management: Web dashboard – no separate EMS infrastructure
• Access control: Graphical web UI, identity- and resource-based

Architecture Comparison

Security: SSL VPN Vulnerabilities vs. WireGuard

FortiGate SSL VPN has produced more critical vulnerabilities in the past two years than any other VPN product on the market. This isn't due to poor development – it's due to the concept. An SSL VPN portal is by design a publicly reachable web application running on a security-critical appliance. Every vulnerability in that web application is a direct path to the core of the network.

FortiOS's codebase spans millions of lines of proprietary code – not auditable, not inspectable, not verifiable. And the patching track record raises concerns: the symlink patch was bypassed. The FortiJump patch was deemed insufficient by security researchers.

NetBird with WireGuard takes a radically different approach:

• No open ports: NetBird peers don't need any port reachable from the internet. The connection is coordinated via NAT traversal and the signal server – data traffic flows directly between peers.
• Minimal codebase: WireGuard consists of ~4,000 lines of code – formally verifiable, easily auditable. Compared to millions of lines of FortiOS, the attack surface is orders of magnitude smaller.
• Cryptography without configuration: ChaCha20, Poly1305, Curve25519, BLAKE2s – no selectable cipher suites, no misconfiguration possible.
• Post-quantum option: Rosenpass offers optional protection against future quantum computer attacks.
• Posture checks: Device state verification before connection (firewall active? OS current? Endpoint security agent running?). Integrations with Microsoft Intune and SentinelOne.
• SCIM provisioning: Automatic on-/offboarding via identity provider. No forgotten VPN account, no manually revoked certificates.
• 100% open source: Every line of code is inspectable, auditable, and verifiable. A fundamental difference from FortiOS.

Security Comparison

Setup and Operations: FortiClient Ecosystem vs. Self-Service Portal

FortiGate + FortiClient: What Operations Really Cost

The Fortinet ecosystem for remote access VPN consists of several components:

FortiGate appliance: The firewall with VPN function. Entry-level models (40F, 60F) cost ~€370–520 (hardware) plus annual FortiGuard licenses (UTP or Enterprise Protection bundle).

FortiClient: The VPN client for endpoints. The basic version (VPN-only) is free, but for zero trust features (ZTNA, posture checks) you need the ZTNA license – from ~$54/endpoint/year for small deployments (25 seats).

FortiClient EMS: The Endpoint Management Server for centralized FortiClient management. Either on-premises (own infrastructure) or as FortiClient Cloud (Fortinet-hosted). Without EMS, no centralized management, no automatic updates, no policy enforcement.

FortiToken: MFA tokens for authentication. Hardware tokens or FortiToken Mobile – additional cost per user.

Ongoing management overhead:

• Renew FortiGuard licenses (annually)
• Apply FortiOS updates (with regression risk)
• Roll out FortiClient updates to all endpoints
• Maintain and update FortiClient EMS
• Manage VPN profiles, configure split tunneling
• SSL VPN to IPsec migration (from FortiOS 7.6)

NetBird: Three Ways to Deploy

NetBird is 100% open source – you choose how to run it:

1. Self-Hosted: Deploy the entire control plane on your own infrastructure. Full control, no third party. Ideal for organizations with their own ops team.

2. NetBird Cloud (netbird.io): The official SaaS solution from NetBird. Quick start with a free plan for small teams, no own infrastructure needed.

3. birdhost (Managed Hosting, 8 Regions Worldwide): Dedicated NetBird instances in 8 regions (DE, NL, US, CA, SGP, JP, SYD, IN). Germany: ISO 27001 & BSI C5 certified data centers. All other locations: data centers with ISO 27001 & SOC 2 Type II. GDPR-compliant (EU locations), with DPA, 24/7 monitoring and support. Certifications held by the respective data center operators.

birdhost: Ready in Minutes

1. Create account on portal.merkaio.com
2. Deploy instance – choose plan, select region (Germany, Netherlands, USA, Canada, Singapore, Japan, Sydney, or India)
3. Open NetBird dashboard – your dedicated instance is ready
4. Install routing peer in office (one command)
5. Onboard employees (client + SSO login)

7 days free trial – own dedicated instance.

Cost Comparison

3-Year Cost Comparison for an SMB (20–50 Employees)

Fortinet prices: estimate based on MSRP with typical reseller discounts (US market). European prices may be higher. Admin personnel costs not included.

For businesses using their FortiGate primarily for VPN, the monthly flat rate from birdhost remains cheaper over three years, mainly because hardware, add-on licenses and ongoing admin effort disappear.

birdhost Volume Pricing

All plans: Unlimited users and devices, no per-user fees, no add-on licenses, cancellable monthly, 8 regions worldwide (DE, NL, US, CA, SGP, JP, SYD, IN; outside the Germany region €119.90 and €229.90 respectively), 24/7 monitoring, updates and patches included. Relay traffic: 2 TB (Startup) and 4 TB (Business) included, then €1/TB.

GDPR and Compliance

FortiGate (Self-Hosted): GDPR responsibility lies with the operator. The appliance sits in your network – good for data sovereignty. But FortiCloud, FortiAnalyzer Cloud, and FortiClient Cloud process metadata in the cloud. Fortinet is a US company headquartered in Sunnyvale, California – potentially subject to the CLOUD Act.

NetBird / birdhost: birdhost offers 8 locations worldwide (Germany, Netherlands, USA, Canada, Singapore, Japan, Sydney, India). All regions use ISO 27001 certified data centers. Germany additionally holds BSI C5 certification, all other locations additionally hold SOC 2 Type II (certifications held by the respective data center operators). For GDPR compliance, European customers select the Germany or Netherlands location. No metadata with US providers when EU location is selected. DPA available directly in the merkaio portal. WireGuard encryption end-to-end – even birdhost cannot decrypt the traffic.

Migration: From FortiClient SSL VPN to NetBird

Migration can happen gradually. NetBird and FortiClient run alongside each other on the same device without issues.

Phase 1 – Test (Day 1): Deploy birdhost instance via portal.merkaio.com. 7 days free. Install routing peer in office, add office network as resource.

Phase 2 – Pilot (Week 1–2): Onboard small group (5–10 employees) onto NetBird in parallel. Configure SSO, define access rules. FortiClient stays active as fallback.

Phase 3 – Rollout (Week 3–4): Migrate all employees to NetBird. Translate access rules from FortiGate SSL VPN policies to NetBird policies – switching from network-based to identity-based rules.

Phase 4 – Decommission SSL VPN: Disable the SSL VPN portal on the FortiGate. The FortiGate stays active for perimeter security – without VPN load and without the SSL VPN portal as attack surface.

Result: Your FortiGate continues doing firewall – but without the attack vector responsible for the CVE series of the last two years. VPN is decoupled, more modern, and more secure.

Full Comparison at a Glance

Decision Guide: When FortiGate, When NetBird?

Staying with FortiGate makes sense if you:

• Use the FortiGate as a complete security platform (IDS/IPS, application control, web filtering, email protection) and VPN is just a side aspect
• Are deeply invested in the Fortinet Security Fabric (FortiAnalyzer, FortiSandbox, FortiSwitch, FortiAP)
• Have a Fortinet-certified partner handling operations and the IPsec migration
• Have the resources to operate and maintain the FortiClient EMS ecosystem

NetBird / birdhost is the better choice if you:

• Use FortiClient SSL VPN as your primary VPN solution and are affected by the SSL VPN removal
• Consider the CVE series and the symlink backdoor an unacceptable risk
• Want to reduce the license and operational overhead of FortiGate + FortiClient EMS + FortiToken
• Want modern access control with SSO, MFA, and automatic provisioning – without FortiToken costs
• Need predictable costs without hardware refresh cycles and license tiers
• Prefer GDPR-compliant managed hosting in Germany
• Want to decouple VPN from the firewall and eliminate the attack surface entirely
• Are looking for a solution that's ready in minutes – not hours or days

The Combination: FortiGate + NetBird

For many businesses, the smartest solution is: FortiGate for perimeter security – NetBird for VPN. The FortiGate continues doing IDS/IPS, application control, web filtering. NetBird handles secure remote access. No SSL VPN portal, no attack surface, no forced IPsec migration.

Conclusion

Fortinet faces a dual problem: the security track record of the last two years – with over 16,000 compromised devices, a symlink backdoor that survives patches, and a series of critical CVEs – has shaken trust in FortiGate SSL VPN. And the decision to remove SSL VPN entirely from FortiOS 7.6.3 forces every FortiGate admin to act.

The automatic answer "we'll just migrate to IPsec" doesn't solve the architectural problem: the firewall remains the central gateway, the FortiClient overhead remains, and the next CVE is just a matter of time.

NetBird offers a fundamental alternative: VPN is decoupled from the firewall, based on WireGuard instead of proprietary code, and eliminates the entire SSL VPN portal attack surface. Combined with managed hosting from birdhost, businesses get a VPN that's ready in minutes, offers identity-based access control, and is hosted in Germany at a predictable flat rate.

Try it now: Start your own NetBird instance via the merkaio self-service portal – 7 days free.

Recommended reading: Sophos VPN Alternative 2026 · OpenVPN Alternative 2026 · NetBird vs. Tailscale 2026 · Twingate Alternative 2026 · NIS2 and VPN Network Security

Sources

• Fortinet: Analysis of Threat Actor Activity (Symlink Backdoor)
• CISA: Fortinet Advisory on Post-Exploitation Technique (April 2025)
• BleepingComputer: Over 16,000 Fortinet Devices Compromised with Symlink Backdoor
• The Hacker News: FortiGate Symlink Exploit – Attackers Retain Access Post-Patching
• ITRES Labs: Bypassing the FortiGate Symlink Patch – CVE-2025-68686 (February 2026)
• Bishop Fox: A Deeper Look at FortiJump – CVE-2024-47575
• Google Cloud: FortiManager Zero-Day Exploitation – CVE-2024-47575
• Rapid7: Fortinet Firewalls Hit with New Zero-Day Attack (January 2025)
• Help Net Security: CVE-2025-59718 – FortiGate Auth Bypass Exploited (December 2025)
• Bitsight: Security Alert FortiBleed – Fortinet VPN Credentials Exposed (June 2026)
• CISA: Urges Hardening of Fortinet Devices After Reports of Credential Exposure (June 18, 2026)
• Fortinet PSIRT: Analysis of Reported Credential Compromise of FortiGate Devices
• Darktrace: Tracking a Real-World Fortinet SSL VPN Attack
• Fortinet: SSL VPN Tunnel Mode Replaced with IPsec VPN (FortiOS 7.6.3)
• Fortinet: Migration from SSL VPN to IPsec VPN
• BOLL: FortiOS 7.6 – Important Change for SSL VPN
• PeerSpot: FortiClient Pros and Cons 2026
• Fortinet: FortiGate Firewalls – Gartner Magic Quadrant Leader 2025
• NetBird GitHub Repository
• NetBird Documentation
• WireGuard Protocol Specification
• birdhost.de – Managed NetBird Hosting