Fortinet Patches Multiple Vulnerabilities Across FortiClient and Other Products
Fortinet released security updates addressing 22 vulnerabilities across multiple products, including FortiWeb, FortiSwitchAX, FortiManager, and FortiClient (Linux). The issues span multiple bug classes (e.g., authentication bypass, heap-based buffer overflow, and cleartext storage of sensitive information) and could enable outcomes such as security bypass, data tampering, denial-of-service, privilege escalation, information disclosure, and in some cases unauthorized code/command execution. Belgium’s CCB urged organizations to patch promptly and noted Fortinet reported no evidence of active exploitation at the time of the advisory.
One of the patched flaws, CVE-2026-24018 (CVSS 7.8), was detailed by the Zero Day Initiative (ZDI-26-186) as a local privilege escalation vulnerability in FortiClient. ZDI reported the flaw stems from handling of certain shared objects: a local attacker with the ability to run low-privileged code can create a symbolic link to coerce a service into loading an arbitrary shared object, enabling execution of attacker-controlled code as root. Fortinet issued a fix and published vendor guidance under FG-IR-26-083.
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How this story unfolded
4 events from the most recent confirmed update back to the earliest known activity.
Belgium CCB urges immediate patching of Fortinet vulnerabilities
Belgium's Centre for Cybersecurity Belgium published a warning that Fortinet had patched 22 vulnerabilities across multiple products and advised organizations to patch immediately. The notice reinforced the urgency of applying Fortinet's available security updates.
ZDI publicly discloses FortiClient vulnerability ZDI-26-186
The Zero Day Initiative publicly released details of CVE-2026-24018 as ZDI-26-186 under coordinated disclosure. The advisory described the improper handling of shared objects in FortiClient and rated the issue CVSS 7.8.
Fortinet releases fixes for CVE-2026-24018 in FortiClient
Fortinet issued an update to remediate the FortiClient local privilege escalation vulnerability and published details in FortiGuard PSIRT advisory FG-IR-26-083. A later Belgian CCB advisory also warned that Fortinet had patched 22 vulnerabilities across multiple products, including this issue.
Astra Security reports FortiClient privilege escalation flaw to Fortinet
Febin Mon Saji of Astra Security reported a local privilege escalation vulnerability in Fortinet FortiClient, later assigned CVE-2026-24018 and tracked by ZDI as ZDI-CAN-27581. The flaw could let a low-privileged local attacker use a symbolic link to have a service load a malicious shared object and execute code as root.
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Fortinet Patches Critical FortiSandbox and FortiManager Command-Execution Flaws
Fortinet issued multiple 2026 security advisories covering a broad set of vulnerabilities across **FortiSandbox, FortiManager, FortiAnalyzer, FortiOS, FortiAP, FortiProxy, FortiPAM, FortiSwitchManager, FortiSwitchAXFixed,** and related cloud offerings. The most severe flaws affect **FortiSandbox**, including `CVE-2026-39808`, an unauthenticated OS command injection bug that could allow arbitrary command execution and full device compromise, `CVE-2026-39813`, a path traversal issue in the JRPC API that may enable authentication bypass and privilege escalation, and `CVE-2026-26083`, a missing authorization flaw that can expose restricted functionality and sensitive sandbox analysis data through the GUI without authentication. National cyber authorities in Canada and Belgium separately warned organizations to apply Fortinet’s fixes immediately. Fortinet also disclosed high-risk issues in management platforms, notably `CVE-2025-54820`, a stack-based buffer overflow in the **FortiManager** `fgtupdates` service that can let remote unauthenticated attackers execute unauthorized commands when the service is enabled, as well as a heap-based buffer overflow affecting **FortiAnalyzer Cloud** and **FortiManager Cloud**. Additional weaknesses across the product line include authentication and MFA bypasses, SQL injection, API denial of service, CLI command injection in FortiAP, CAPWAP daemon memory corruption in FortiOS, stored and reflected XSS, improper access control, and credential exposure. Fortinet advised customers to upgrade to fixed releases, disable exposed services such as `fgtupdates` where possible, restrict CLI, SSH, and API access, and monitor logs for anomalous authentication, privilege escalation, and endpoint activity.
Jun 18, 2026
Fortinet Patches Critical RCE Flaws in FortiAuthenticator and FortiSandbox
Fortinet released fixes for two **critical** vulnerabilities that could let remote, unauthenticated attackers run unauthorized code or commands on exposed systems. The first, **`CVE-2026-44277`**, is an improper access control flaw in **FortiAuthenticator** with a **CVSS 9.1** rating; it affects versions **8.0.0**, **8.0.2**, **6.6.0-6.6.8**, and **6.5.0-6.5.6**, and was patched in **8.0.3**, **6.6.9**, and **6.5.7**. Fortinet said the issue stems from insufficient authorization checks on API endpoints and could allow unauthorized API access, privilege escalation, and command execution, while **FortiAuthenticator Cloud is not affected**. Fortinet also disclosed **`CVE-2026-26083`**, a **CVSS 9.1** missing-authorization flaw in the **FortiSandbox** Web UI that impacts **FortiSandbox**, **FortiSandbox Cloud**, and **FortiSandbox PaaS**, potentially enabling arbitrary code execution across on-premises and cloud deployments. Canada’s Cyber Centre warned that the advisories span multiple Fortinet products and urged administrators to review Fortinet PSIRT notices and apply updates promptly. Public reporting said Fortinet had not observed either flaw being exploited in the wild at disclosure, but the breadth of affected security infrastructure and Fortinet’s history of high-value exploitation have increased urgency around patching exposed appliances.
May 16, 2026
Multiple Vulnerabilities in Fortinet Products Enable Arbitrary Code Execution and Information Disclosure
Several Fortinet products, including FortiWeb, FortiClient, FortiExtender, FortiMail, FortiPAM, FortiSandbox, FortiADC, FortiVoice, FortiOS, and FortiProxy, have been found to contain multiple vulnerabilities, some of which could allow for arbitrary code execution. The most severe of these vulnerabilities, such as the FortiWeb RCE flaw (CVE-2025-58034), is under active exploitation and has been added to CISA's Known Exploited Vulnerabilities (KEV) catalog. Additionally, a vulnerability in FortiClient for Windows involving active debug code could allow a local attacker to retrieve saved VPN user passwords, posing a significant risk of information disclosure. Security advisories urge organizations using affected Fortinet products to review available patches and mitigations immediately. The vulnerabilities impact a wide range of Fortinet's security and networking solutions, increasing the urgency for prompt remediation to prevent potential exploitation and compromise of sensitive assets.
Mar 21, 2026