Source: Fortinet PSIRT

19 stories

Fortinet fixed an improper access control flaw (CVSS 8.9) in FortiSandbox, FortiSandbox Cloud, and FortiSandbox PaaS letting unauthenticated attackers access sensitive information.

Fortinet advisory FG-IR-26-166 discloses an improper access control vulnerability (CWE-284) in the FortiSandbox, FortiSandbox Cloud, and FortiSandbox PaaS web UI, rated CVSSv3 8.9. The advisory title indicates unauthenticated control of NAT rules leading to exposure of sensitive information. An unauthenticated attacker can access sensitive data via crafted HTTP requests. The advisory was revised on 2026-09-08.

Fortinet PSIRTSep 8, 07:00 UTC · 7d agoAdvisory

Null Pointer Dereference in Log Report

Fortinet patched a low-severity null pointer dereference (CVSS 2.5) in FortiOS, FortiProxy, and FortiPAM that lets authenticated attackers crash the httpsd daemon.

Fortinet advisory FG-IR-26-173 describes a NULL pointer dereference vulnerability (CWE-476) in FortiOS, FortiProxy, and FortiPAM, scored CVSSv3 2.5. An authenticated attacker can crash the httpsd daemon via crafted HTTP requests, causing a denial of service. The advisory was revised on 2026-09-08.

Fortinet PSIRTSep 8, 07:00 UTC · 7d agoAdvisory

Arbitrary process termination from exposed minifilter communication port

Fortinet FortiClient Windows fortimon3 driver flaw (CVSS 4.7) lets authenticated attackers terminate arbitrary processes via exposed minifilter communication port.

Fortinet advisory FG-IR-26-165 discloses an unverified ownership vulnerability (CWE-283, CVSSv3 4.7) in the FortiClient Windows fortimon3 minifilter driver. An authenticated attacker can terminate arbitrary processes through an exposed minifilter communication port. The advisory was revised on 2026-09-08.

Fortinet PSIRTSep 8, 07:00 UTC · 7d agoAdvisory

ZTNA Portal Improper Certificate Validation

Fortinet fixed an improper certificate validation flaw (CVSS 7.3) in FortiOS and FortiProxy Agentless ZTNA portal enabling unauthenticated man-in-the-middle attacks on backend traffic.

Fortinet advisory FG-IR-26-174 discloses an improper certificate validation vulnerability (CWE-295) in the FortiOS and FortiProxy Agentless ZTNA portal, rated CVSSv3 7.3. A remote and unauthenticated attacker can perform a man-in-the-middle attack on the communication channel between the ZTNA portal and the backend destination website. The advisory was revised on 2026-09-08.

Fortinet PSIRTSep 8, 07:00 UTC · 7d agoAdvisory

Uncontrolled Resource Consumption in SNMP

Uninitialized variable flaw (CVSS 5.9) in FortiAnalyzer's SNMP daemon lets remote authenticated attackers cause denial of service via SNMP GETBULK requests.

Fortinet advisory FG-IR-26-172 describes a use of uninitialized variable vulnerability (CWE-457) in the FortiAnalyzer SNMP daemon, scored CVSSv3 5.9. A remote authenticated attacker with user-level permissions can cause a denial of service via SNMP GETBULK requests. The advisory was revised on 2026-09-08.

Fortinet PSIRTSep 8, 07:00 UTC · 7d agoAdvisory

JWT used for authentication in web GUI signed with static key

Fortinet warns that FortiMonitorOnSight's web GUI uses JWTs signed with a static key, enabling remote unauthenticated authentication bypass.

Fortinet advisory FG-IR-26-170 discloses a CVSS 9.6 vulnerability (CWE-540, sensitive information in source code) in the FortiMonitorOnSight web portal. The web GUI's JWT authentication tokens are signed with a static key, allowing a remote unauthenticated attacker to bypass authentication via forged or reused JWTs. The advisory was revised on September 8, 2026.

Fortinet PSIRTSep 8, 07:00 UTC · 7d agoAdvisory

Cron Job Injection in Remote Backup

Fortinet FortiSandbox command injection flaw (CVSS 6.7) in remote backup cron jobs lets privileged attackers execute arbitrary code via crafted HTTP requests.

Fortinet advisory FG-IR-26-167 discloses a command injection vulnerability (CWE-77, CVSSv3 6.7) in FortiSandbox's remote backup cron job functionality. A privileged attacker can execute unauthorized code or commands via crafted HTTP requests. The advisory was revised on 2026-09-08.

Fortinet PSIRTSep 8, 07:00 UTC · 7d agoAdvisory

Workflow session email approval process bypass

Fortinet disclosed an improper access control flaw (CVSS 4.7) in FortiManager allowing administrators to bypass workflow session email approval via crafted HTTP requests.

Fortinet advisory FG-IR-26-171 covers an improper access control vulnerability (CWE-284) in FortiManager, rated CVSSv3 4.7. An administrator can bypass the approval process for workflow sessions via crafted HTTP or HTTPS requests. The advisory was revised on 2026-09-08.

Fortinet PSIRTSep 8, 07:00 UTC · 7d agoAdvisory

Improper Authentication of FortiPAM Server

Fortinet discloses CVSS 9.1 improper authentication in FortiPAM's Chrome extension allowing unauthenticated attackers to proxy victims' browser traffic.

Fortinet advisory FG-IR-26-168 describes an improper authentication vulnerability (CWE-287) rated 9.1 in the Fortinet Privileged Access Agent Chrome Extension. A remote unauthenticated attacker could proxy a user's browser traffic through attacker-controlled servers if the user visits a malicious website. The advisory was revised on September 8, 2026.

Fortinet PSIRTSep 8, 07:00 UTC · 7d agoAdvisory

Open Redirect on FortiSIEM

Fortinet disclosed an open redirect flaw (CVSS 2.8) in FortiSIEM allowing authenticated attackers to redirect users to arbitrary websites via crafted HTTP requests.

Fortinet advisory FG-IR-26-169 covers an open redirect vulnerability (CWE-601) in FortiSIEM, rated CVSSv3 2.8. An authenticated attacker can cause a redirection to any website via specially crafted HTTP requests. The advisory was revised on 2026-09-08.

Fortinet PSIRTSep 8, 07:00 UTC · 7d agoAdvisory

Broken Access control on Websocket streams

Fortinet FortiSOAR access control flaw (CVSS 4.9) lets zero-permission authenticated attackers subscribe to and inject broadcast messages into websocket streams.

Fortinet advisory FG-IR-26-164 discloses an improper access control vulnerability (CWE-284, CVSSv3 4.9) in FortiSOAR. An authenticated attacker with zero permissions can subscribe to websocket streams and topics and inject broadcast messages via crafted websocket requests. The advisory was revised on 2026-09-08.

Fortinet PSIRTSep 8, 07:00 UTC · 7d agoAdvisory

Content-Encoding WAF Evasion

FortiWeb WAF policies can be bypassed by unauthenticated attackers using crafted Content-Encoding requests (CVSS 4.8).

Fortinet disclosed an incomplete list of disallowed inputs (CWE-184) in FortiWeb's WAF, tracked as FG-IR-26-157. An unauthenticated attacker can bypass WAF policies using specifically crafted requests with crafted Content-Encoding values. The issue carries a CVSSv3 score of 4.8 and was revised on 2026-08-12. The advisory does not report active exploitation.

Fortinet PSIRTAug 12, 07:00 UTC · Aug 12, 2026Advisory

Heap overflow in kernel driver due to missing size validation

Fortinet fixes a CVSS 7.3 heap overflow in the FortiClient Windows kernel driver enabling code execution via crafted DNS responses.

Fortinet PSIRT advisory FG-IR-26-156, revised 2026-08-12, describes a heap-based buffer overflow (CWE-120, buffer copy without checking input size) in the FortiClient Windows kernel driver, scored CVSSv3 7.3. An unauthenticated attacker positioned to alter or craft DNS responses for a targeted host could execute arbitrary code via malicious packets. No CVE identifier or exploitation status is provided in the advisory text, so administrators should check the full bulletin for affected versions and fixed releases.

Fortinet PSIRTAug 12, 07:00 UTC · Aug 12, 2026Advisory

Broken access control in the RADIUS type admin group

FortiWeb RADIUS admin authentication flaw (CVSS 8.8) permits remote GUI/CLI login with random credentials under specific non-default settings.

Fortinet advisory FG-IR-26-158 describes an improper authentication flaw (CWE-287) in FortiWeb's Remote RADIUS-type admin authentication, scored CVSSv3 8.8. When the configuration uses specific non-default settings, a remote unauthenticated attacker can log into the FortiWeb GUI or CLI with a random username and password. The advisory was revised on 2026-08-12 and does not state that exploitation has been observed.

Fortinet PSIRTAug 12, 07:00 UTC · Aug 12, 2026Advisory

FGFM Authentication Weakening via CLI Configuration

FortiManager FGFM flaw (CVSS 7.3) lets an attacker with a valid certificate impersonate any managed FortiGate under a specific CLI option.

Fortinet advisory FG-IR-26-160 describes an authentication bypass via alternate path (CWE-288) in FortiManager and FortiManager Cloud, scored CVSSv3 7.3. A remote unauthenticated attacker holding a valid certificate can impersonate any FortiGate managed by the affected FortiManager when a specific CLI option is set. The impersonation is performed with crafted FGFM protocol requests. The advisory was revised on 2026-08-12 and does not report active exploitation.

Fortinet PSIRTAug 12, 07:00 UTC · Aug 12, 2026Advisory

Server-Side Request Forgery (SSRF)

Fortinet discloses a low-severity SSRF in the FortiSIEM GUI allowing authenticated attackers to send requests from targeted devices.

Fortinet PSIRT advisory FG-IR-26-159, revised 2026-08-12, describes a server-side request forgery (CWE-918) in the FortiSIEM GUI, scored CVSSv3 3.4. An authenticated attacker can send HTTP requests originating from the targeted device via specially crafted requests, potentially enabling internal network probing. No CVE identifier or exploitation status is included in the advisory text.

Fortinet PSIRTAug 12, 07:00 UTC · Aug 12, 2026Advisory

HTTP/2 Bomb CVE-2026-49975

Fortinet advisory details CVE-2026-49975, an Apache HTTP Server HTTP/2 flaw enabling denial of service, affecting versions 2.4.17 through 2.4.67.

Fortinet PSIRT advisory FG-IR-26-163, revised 2026-08-19, covers CVE-2026-49975, a memory allocation with excessive size value flaw (HTTP/2 bomb) in Apache HTTP Server's mod_http2, scored CVSSv3 5.8. Malicious HTTP requests can cause a denial of service, and affected versions span Apache HTTP Server 2.4.17 through 2.4.67. The advisory text does not state which Fortinet product bundles the affected Apache component or whether exploitation has been observed.

Fortinet PSIRTAug 12, 07:00 UTC · Aug 12, 2026Advisory CVE-2026-49975

Stack buffer overflow in WAD

FortiOS explicit proxy WAD daemon stack buffer overflow (CVSS 5.1) allows code execution only with Kerberos and SOCKS configured.

Fortinet advisory FG-IR-26-161 describes a stack-based buffer overflow (CWE-121) in the WAD daemon of FortiOS explicit proxy, scored CVSSv3 5.1. Exploitation requires an attacker able to bypass stack protection and ASLR, and the explicit proxy must be configured with Kerberos authentication and SOCKS enabled. If successful, it yields arbitrary code or command execution in the WAD daemon context via crafted sockets. No exploitation is reported in the advisory.

Fortinet PSIRTAug 12, 07:00 UTC · Aug 12, 2026Advisory

UI DoS attack

FortiOS web interface is vulnerable to unauthenticated slow HTTP denial-of-service attacks via crafted requests (CVSS 5.0).

Fortinet advisory FG-IR-26-162 details an unbounded resource allocation flaw (CWE-770) in FortiOS, scored CVSSv3 5.0. An unauthenticated attacker can launch a slow HTTP denial-of-service attack against the FortiOS web interface using crafted HTTP requests. The advisory was revised on 2026-08-12 and does not state that exploitation has been observed.

Fortinet PSIRTAug 12, 07:00 UTC · Aug 12, 2026Advisory