CVE-2026-24018: Fortinet FortiClient Local Privilege Escalation Vulnerability Disclosed
A local privilege escalation vulnerability in Fortinet FortiClient, tracked as CVE-2026-24018, allows attackers to gain root access via a symbolic link attack on shared objects.
Fortinet has disclosed a local privilege escalation vulnerability in its FortiClient endpoint security software, designated CVE-2026-24018. The flaw, reported by Febin Mon Saji from Astra Security, allows an attacker with low-privileged code execution on a target system to create a symbolic link and abuse the FortiClient service to load arbitrary shared object loading service. This can lead to arbitrary code execution in the context of root, granting root access, effectively compromising the entire system.
The vulnerability resides in the handling of certain shared objects within FortiClient. By crafting a symbolic link, an attacker can redirect the service to load and load arbitrary shared objects, bypassing normal security controls. The CVSS score for this vulnerability is 7.8, with a vector of AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, indicating a high impact on confidentiality, integrity, and availability. The attack vector is local, requiring the attacker to already have low-privileged code execution on the target system.
FortiClient is widely deployed across enterprise environments for endpoint protection, VPN connectivity, and compliance enforcement. The vulnerability affects all versions of FortiClient prior to the patch released by Fortinet. Given the widespread use of FortiClient in corporate networks, successful exploitation could allow an attacker to move laterally, install persistent backdoors, or exfiltruncate logs, or exfiltrate sensitive data.
Fortinet has released an update to address CVE-2026-24018 to address this vulnerability. The advisory is available at FortiGuard PSIRT. Users are strongly advised to apply the latest FortiClient update immediately. The disclosure timeline shows the vulnerability was reported to Fortinet on October 29, 2025, and the coordinated public release of the advisory occurred on March 10, 2026.
This vulnerability is part of a broader trend of local privilege escalation flaws in endpoint security products that run with elevated privileges. The use of symbolic links to exploit shared object loading is a well-known technique, but it remains effective when vendors fail to properly validate file paths or restrict the loading of arbitrary libraries. The discovery by Febin Mon Saji highlights the ongoing importance of security research in identifying such weaknesses.
Organizations using FortiClient should prioritize patching, especially on systems where users have local access. In the interim, administrators can restrict local user permissions and monitor for unusual symbolic link creation or unexpected shared object loading. The vulnerability has not been reported as exploited in the wild, but the public disclosure of technical details increases the risk of attackers developing exploits.
This disclosure underscores the need for robust input validation and secure coding practices in software that runs with elevated privileges. As endpoint security tools become more complex, the attack surface for local privilege escalation grows. Fortinet's response with a timely patch demonstrates a commitment to security, but users must act quickly to close this window of vulnerability.