Out-of-Bounds Write in FortiOS Allows Remote Code Execution

A out-of-bounds write vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11 allows attacker to execute unauthorized code or commands via specially crafted packets.

A stack-based buffer overflow vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions allows attacker to execute unauthorized code or commands via specially crafted packets

An incorrect privilege assignment vulnerability [CWE-266] in FortiOS Security Fabric version 7.6.0 through 7.6.2, 7.4.0 through 7.4.7, 7.2 all versions, 7.0 all versions, 6.4 all versions, may allow a remote authenticated attacker with high privileges to escalate their privileges to super-admin via registering the device to a malicious FortiManager.

An Improper Validation of Certificate with Host Mismatch vulnerability [CWE-297] in FortiProxy version 7.6.1 and below, version 7.4.8 and below, 7.2 all versions, 7.0 all versions and FortiOS version 7.6.2 and below, version 7.4.8 and below, 7.2 all versions, 7.0 all versions ZTNA proxy may allow an unauthenticated attacker in a man-in-the middle position to intercept and tamper with connections to the ZTNA proxy

An Integer Overflow or Wraparound vulnerability [CWE-190] in FortiOS version 7.6.2 and below, version 7.4.7 and below, version 7.2.10 and below, 7.2 all versions, 6.4 all versions, FortiProxy version 7.6.2 and below, version 7.4.3 and below, 7.2 all versions, 7.0 all versions, 2.0 all versions and FortiPAM version 1.5.0, version 1.4.2 and below, 1.3 all versions, 1.2 all versions, 1.1 all versions, 1.0 all versions SSL-VPN RDP and VNC bookmarks may allow an authenticated user to affect the device SSL-VPN availability via crafted requests.

An Improper Certificate Validation vulnerability [CWE-295] in FortiOS version 7.6.1 and below, version 7.4.7 and below may allow an EAP verified remote user to connect from FortiClient via revoked certificate.

An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] in FortiOS 7.4.0 through 7.4.7, 7.2.0 through 7.2.11, 7.0.6 and above; and FortiProxy 7.6.0 through 7.6.2, 7.4.0 through 7.4.8, 7.2 all versions, 7.0.5 and above may allow an authenticated attacker to elevate their privileges via triggering a malicious Webhook action in the Automation Stitch component.

An Improperly Implemented Security Check for Standard vulnerability [CWE-358] in FortiOS version 7.6.0, version 7.4.7 and below, 7.0 all versions, 6.4 all versions and FortiProxy version 7.6.1 and below, version 7.4.8 and below, 7.2 all versions, 7.0 all versions may allow a remote unauthenticated user to bypass the DNS filter via Apple devices.

A out-of-bounds write in Fortinet FortiOS versions 7.6.0, 7.4.0 through 7.4.6, 7.2.0 through 7.2.10, 7.0.0 through 7.0.16, 6.4.0 through 6.4.15 allows attacker to trigger a denial of service via specially crafted packets.

An Insufficient Session Expiration vulnerability [CWE-613] in FortiOS SSL-VPN version 7.6.0, version 7.4.6 and below, version 7.2.10 and below, 7.0 all versions, 6.4 all versions may allow an attacker in possession of a cookie used to log in the SSL-VPN portal to log in again, although the session has expired or was logged out.

A storing passwords in a recoverable format in Fortinet FortiOS 7.4.0 through 7.4.8, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions allows attacker to information disclosure via modification of LDAP server IP to point to a malicious server.

A use of externally-controlled format string vulnerability in Fortinet FortiOS 7.6.0 through 7.6.4, FortiOS 7.4.0 through 7.4.9, FortiOS 7.2.0 through 7.2.11, FortiOS 7.0 all versions allows an authenticated admin to execute unauthorized code or commands via specifically crafted configuration.

An Improper Verification of Source of a Communication Channel vulnerability [CWE-940] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.4, FortiOS 7.4.0 through 7.4.9, FortiOS 7.2 all versions, FortiOS 7.0 all versions may allow an authenticated user with knowledge of FSSO policy configurations to gain unauthorized access to protected network resources via crafted requests.

An inconsistent interpretation of http requests ('http request smuggling') vulnerability in Fortinet FortiOS 7.6.0, FortiOS 7.4.0 through 7.4.9, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4.3 through 6.4.16 may allow an unauthenticated attacker to smuggle an unlogged http request through the firewall policies via a specially crafted header

Missing Authentication Allows Unauthenticated Code Execution in FortiOS

A missing authentication for critical function vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11, FortiOS 7.0.0 through 7.0.17, FortiOS 6.4 all versions, FortiOS 6.2.9 through 6.2.17 allows attacker to execute unauthorized code or commands via specially crafted packets.

An insufficient session expiration vulnerability [CWE-613] vulnerability in Fortinet FortiOS 7.4.0, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions allows attacker to maintain access to network resources via an active SSLVPN session not terminated after a user's password change under particular conditions outside of the attacker's control

An authentication bypass using an alternate path or channel [CWE-288] vulnerability in Fortinet FortiOS 6.4.0 through 6.4.15, FortiOS 6.2.0 through 6.2.16, FortiOS 6.0 all versions, FortiPAM 1.2.0, FortiPAM 1.1.0 through 1.1.2, FortiPAM 1.0.0 through 1.0.3, FortiProxy 7.4.0 through 7.4.2, FortiProxy 7.2.0 through 7.2.8, FortiProxy 7.0.0 through 7.0.15, FortiSwitchManager 7.2.0 through 7.2.3, FortiSwitchManager 7.0.0 through 7.0.3 allows an unauthenticated attacker to seize control of a managed device via crafted FGFM requests, if the device is managed by a FortiManager, and if the attacker knows that FortiManager's serial number.

An Authentication Bypass by Primary Weakness vulnerability [CWE-305] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.4 may allow an unauthenticated attacker to bypass LDAP authentication of Agentless VPN or FSSO policy, when the remote LDAP server is configured in a specific way.

LDAP Credentials Decryption via Default Encryption Key in FortiOS 7.6.6

Fortinet FortiOS through 7.6.6 allows attackers to decrypt LDAP credentials stored in device configuration files, as exploited in the wild from 2025-12-16 through 2026 (by default, the encryption key is the same across all customers' installations). NOTE: the Supplier's position is that the instance of CWE-1394 is not a vulnerability because customers "are supposed to enable" a non-default option that eliminates the weakness. However, that non-default option can disrupt functionality as shown in the "Managing FortiGates with private data encryption" document, and is therefore intentionally not a default option.

The Internet Key Exchange version 1 (IKEv1) implementations in Fortinet FortiOS 2.50, 2.80 and 3.0, FortiClient 2.0,; and FortiManager 2.80 and 3.0 allow remote attackers to cause a denial of service (termination of a process that is automatically restarted) via IKE packets with invalid values of certain IPSec attributes, as demonstrated by the PROTOS ISAKMP Test Suite for IKEv1. NOTE: due to the lack of details in the vendor advisory, it is unclear which of CVE-2005-3666, CVE-2005-3667, and/or CVE-2005-3668 this issue applies to.