Search: “Fortinet PSIRT”

Fortinet security advisory (AV26-023) - Update 1

CISA added Fortinet CVE-2025-25249, a heap-based buffer overflow in the cw_acd daemon, to its KEV catalog; Canadian Cyber Centre urges patching.

The Canadian Centre for Cyber Security updated advisory AV26-023, which relays January 2026 Fortinet advisories covering FortiFone, FortiOS, FortiSASE, FortiSIEM, and FortiSwitchManager. On September 9, 2026, CISA added CVE-2025-25249, a heap-based buffer overflow in the cw_acd daemon, to its Known Exploited Vulnerabilities catalog. Related Fortinet flaws include unauthenticated local configuration access (CVE-2025-47855) and unauthenticated remote command injection (CVE-2025-64155). Administrators should review the advisories and apply available updates.

Canadian Centre for Cyber Security·updated Sep 10, 11:26 UTC · 6d ago·first Sep 9, 19:57 UTC · 6d agoExploit / PoC in the wild 4 sourcesCVE-2025-25249CVE-2025-47855CVE-2025-64155

Fortinet Patches Critical Vulnerabilities in FortiMonitorOnSight, Chrome Extension

Fortinet patched 10 vulnerabilities including two critical authentication flaws, CVE-2026-84390 (CVSS 9.6) and CVE-2026-84388 (CVSS 9.1), in FortiMonitorOnSight and the FortiPAM Chrome extension.

Fortinet's September patch release fixes CVE-2026-84390, a sensitive-information issue in the FortiMonitorOnSight web portal that lets unauthenticated attackers bypass authentication with forged or reused JWTs. CVE-2026-84388 is an improper authentication flaw in the Fortinet Privileged Access Agent Chrome extension that can allow attackers to proxy a user's browser traffic via a malicious website, requiring upgrades to both FortiPAM 1.9.1/1.8.4 and extension 8.0.1.123+. High-severity information disclosure in FortiSandbox (CVE-2026-26084) and man-in-the-middle risk in the FortiOS/FortiProxy Agentless ZTNA portal (CVE-2026-84393) were also fixed, alongside medium/low issues across FortiManager, FortiAnalyzer, FortiSOAR, FortiClient, FortiSIEM and others. Fortinet did not indicate any of the flaws are being exploited in the wild.

SecurityWeek·Sep 9, 14:33 UTC · 6d agoVulnerability 2 sourcesCVE-2026-84390CVE-2026-84388CVE-2026-26084+1 CVEs

Fortinet FortiSandbox Vulnerability Allows Unauthenticated Attackers to Access Sensitive Information

Fortinet fixed CVE-2026-26084, an unauthenticated access-control flaw in FortiSandbox GUI rated 8.9 CVSS, with no known exploitation yet.

Fortinet disclosed CVE-2026-26084 (advisory FG-IR-26-166), a CWE-284 improper access control flaw in the GUI of FortiSandbox, FortiSandbox Cloud and FortiSandbox PaaS, rated 8.9 CVSS v3.1. An unauthenticated remote attacker can send specially crafted HTTP requests to control NAT rules and expose sensitive information. Affected versions include FortiSandbox 4.4.0-4.4.8 and 5.0.0-5.0.5 (plus Cloud/PaaS 5.0.4-5.0.5), fixed in 4.4.9 and 5.0.6. Fortinet researcher Adham El Karn found the flaw internally and the September 8 advisory reports no known exploitation.

GBHackers·Sep 9, 07:15 UTC · 7d agoVulnerabilityCVE-2026-26084

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 PSIRT·Aug 12, 07:00 UTC · Aug 12, 2026AdvisoryCVE-2026-49975

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 PSIRT·Aug 12, 07:00 UTC · Aug 12, 2026Advisory

Fortinet Confirms Critical Zero Day

Fortinet has confirmed a critical zero-day vulnerability; the available headline provides no product, CVE, or exploitation details.

Infosecurity Magazine's headline states that Fortinet has confirmed a critical zero-day vulnerability. The available source text contains no additional details on affected products, CVE identifiers, exploitation status, or available fixes. Defenders should treat specifics as unconfirmed pending a vendor advisory.

Infosecurity Magazine·Aug 16, 00:00 UTC · Aug 16, 2026Exploit / PoC in the wild

Fortinet Vulnerability Ransomware

Ransomware operators are exploiting a Fortinet vulnerability, per the Infosecurity Magazine headline; article details unavailable.

Infosecurity Magazine's headline indicates ransomware activity tied to a Fortinet vulnerability. The article body was not available, so the specific CVE, affected versions and victim details are unconfirmed.

Infosecurity Magazine·Aug 16, 00:00 UTC · Aug 16, 2026Exploit / PoC in the wild

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 PSIRT·Aug 12, 07:00 UTC · Aug 12, 2026Advisory

74,000 Fortinet firewall credentials exposed in FortiBleed data leak

Help Net Security·Aug 3, 13:19 UTC · Aug 3, 2026Data breach

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 PSIRT·Sep 8, 07:00 UTC · 8d 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 PSIRT·Sep 8, 07:00 UTC · 8d agoAdvisory1

FortiOS and FortiProxy ZTNA Validation Vulnerability Allows Attacker to Perform a Man-in-the-Middle Attack

Fortinet discloses high-severity certificate validation flaw CVE-2026-84393 in FortiOS and FortiProxy Agentless ZTNA portals enabling unauthenticated man-in-the-middle attacks.

Fortinet disclosed CVE-2026-84393 (CVSSv3 7.3, CWE-295) on September 8, 2026 under advisory FG-IR-26-174: improper certificate validation in the Agentless ZTNA portal of FortiOS and FortiProxy. An unauthenticated attacker on the network path could present a forged or mismatched certificate and intercept or tamper with traffic between the portal and backend destinations, with impact classified as information disclosure. Affected versions are FortiOS 7.6.1 through 7.6.6 and FortiProxy 7.6.2 through 7.6.6; the 8.0, 7.4 and 7.2 branches of both products are unaffected. Fortinet urges upgrading to 7.6.7 or later and reports no evidence of exploitation in the wild.

Cyber Security News·Sep 8, 17:15 UTC · 7d agoVulnerabilityCVE-2026-84393

Hackers Deploy Casbaneiro Banking Trojan That Activates When Victims Open Bank Websites

Fortinet details Casbaneiro banking Trojan campaign hitting Latin American bank customers via invoice-themed PDF phishing, with AutoIt loading, RegSvcs.exe injection, and bank-site-triggered activation.

Fortinet identified an August 2026 Casbaneiro banking Trojan campaign targeting users in Argentina, Peru, Colombia, and Mexico through phishing PDFs styled as urgent invoices or legal notices. The staged chain uses IP-based geo-filtering, a Base64-encoded ZIP, an HTA file, and a legitimate AutoIt interpreter before injecting into RegSvcs.exe or mobsync.exe and persisting via a Startup shortcut. The Trojan exfiltrates address book and Outlook data unencrypted, stays dormant until victims visit targeted bank sites, then accepts commands for keyboard control, clipboard pasting, file execution, and command execution. It uses an expected HTTP 403 response from a second server and malformed HTTP requests to complicate network analysis.

Cyber Security News·Sep 14, 08:42 UTC · 2d agoMalware in the wild

The 12 Best Managed Firewall Services, Compared and Priced

GBHackers compares 12 managed firewall service providers, naming Fortinet best value and Secureworks best detection while flagging recent ownership changes.

The buyer's guide evaluates 12 managed firewall/MSSP providers across cost tiers, contract terms, and service models. Fortinet is rated best value, Secureworks best detection, NTT Data best global reach, and Cato Networks best for organizations wanting to stop owning firewalls. The article highlights that Secureworks was acquired by Sophos for roughly $859 million in February 2025, the Trustwave-Cybereason merger was terminated in March 2025, LevelBlue is the rebranded AT&T Cybersecurity business, and Comcast Business absorbed Masergy.

GBHackers·Sep 8, 10:20 UTC · 8d agoIndustry 2 sources

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 PSIRT·Sep 8, 07:00 UTC · 8d 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 PSIRT·Sep 8, 07:00 UTC · 8d agoAdvisory

Thai Broadband Provider Hacked via Fortinet Vulnerability

Hackers exploited Fortinet CVE-2024-21762 RCE to breach Thai broadband provider 3BB, deploying MeshCentral backdoors and credential-harvesting tools across its network.

Hunt.io uncovered an intrusion staging directory in Thailand containing 298 files of custom tooling built for Triple T Broadband (3BB) and its former owner Jasmine. Initial access came via fingerprinting a FortiGate SSL-VPN appliance and exploiting CVE-2024-21762 for remote code execution, after probing CVE-2018-13379, CVE-2022-42475, and CVE-2023-27997. The actor also probed F5 BIG-IP for CVE-2021-22986, CVE-2022-1388, and CVE-2023-46747, escalated privileges with PwnKit and Dirty COW, used MeshCentral as a C2 backdoor, harvested SSH/database/SNMP/Radius credentials, deployed PHP web shells, and ran cleanup scripts to hide the intrusion.

SecurityWeek·Sep 15, 13:33 UTC · 23h agoThreat actor in the wildCVE-2018-13379CVE-2022-42475CVE-2023-27997+4 CVEs

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 PSIRT·Sep 8, 07:00 UTC · 8d 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 PSIRT·Sep 8, 07:00 UTC · 8d agoAdvisory

Fortra security advisory (AV26-906)

Canada's Cyber Centre advises that Fortra GoAnywhere MFT Endpoint versions prior to 7.10.2 are affected by a path traversal vulnerability.

The Canadian Centre for Cyber Security issued advisory AV26-906 noting that Fortra GoAnywhere MFT Endpoint versions prior to 7.10.2 are affected by a path traversal vulnerability. The advisory was published September 10, 2026, referencing Fortra's own security advisory. No exploitation details or CVE id are provided; administrators are urged to review the links and apply the 7.10.2 update.

Canadian Centre for Cyber Security·Sep 10, 12:38 UTC · 6d agoAdvisory

Gunra Ransomware Exploits Fortinet FortiOS, FortiProxy Flaws to Breach Networks

CISA, FBI, and South Korean agencies warn Gunra ransomware, with 51 victims since April 2025, exploits Fortinet flaws for double-extortion attacks on critical infrastructure.

CISA, the FBI, and South Korean agencies warned of Gunra ransomware attacks targeting healthcare, financial services, government, and professional services worldwide. The Conti-derived operation exploits internet-facing Fortinet FortiOS and FortiProxy flaws CVE-2024-55591 and CVE-2025-24472 for initial access, then deploys double extortion with Salsa20/ChaCha20 encryption and publishes non-payers on a leak site within five to seven days. Ransomware.Live lists 51 victims since April 2025, mostly in South Korea, Brazil, Spain, Thailand, and Hong Kong. The group uses Impacket tools for SMB lateral movement and NTDS credential dumping, tampers with VDI authentication to accept a designated OTP value to bypass MFA, and launched a RaaS affiliate program in January 2026 under the new alias Golden Community.

The Hacker News·Aug 12, 08:42 UTC · Aug 12, 2026Ransomware in the wildCVE-2024-55591CVE-2025-24472

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 PSIRT·Sep 8, 07:00 UTC · 8d agoAdvisory

Unauthenticated Control of NAT Rules Leading to Exposure of Sensitive Information

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 PSIRT·Sep 8, 07:00 UTC · 8d agoAdvisory

FortiSandbox Vulnerability Allows Attackers to Access Sensitive Information via Crafted HTTP Requests

Fortinet disclosed CVE-2026-26084 (CVSS 8.9), an unauthenticated information-disclosure flaw in the FortiSandbox web UI, urging upgrades.

Fortinet patched CVE-2026-26084, a CWE-284 improper access control flaw in the shared web UI of FortiSandbox, FortiSandbox Cloud, and FortiSandbox PaaS that lets unauthenticated attackers read sensitive data via crafted HTTP requests. Affected releases include FortiSandbox 5.0.0-5.0.5 and 4.4.0-4.4.8, Cloud 5.0.4-5.0.5, and PaaS 5.0.4-5.0.5; fixes arrive in 5.0.6+ and 4.4.9+, while FortiSandbox 5.2 and Cloud 4.4 are unaffected. The issue was found internally by Fortinet's Product Security team, and the company reports no evidence of exploitation in the wild. Disclosure carries only confidentiality impact, but exposed sandbox configurations and logs could aid follow-on attacks.

Cyber Security News·Sep 9, 03:08 UTC · 7d agoVulnerabilityCVE-2026-26084

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 PSIRT·Aug 12, 07:00 UTC · Aug 12, 2026Advisory