CISA: Fortinet Releases Guidance to Address Ongoing Exploitation of Authentication Bypass Vulnerability CVE-2026-24858


Newly disclosed vulnerability Common Vulnerabilities and Exposures (CVE)-2026-24858 [Common Weakness Enumeration (CWE)-288: Authentication Bypass Using an Alternate Path or Channel] allows malicious actors with a FortiCloud account and a registered device to log in to separate devices registered to other users in FortiOS, FortiManager, FortiWeb, FortiProxy, and FortiAnalyzer, if FortiCloud single sign on (SSO) is enabled on devices.

Users are vulnerable to CVE-2026-24858 even if they updated Fortinet devices to address previously disclosed FortiCloud SSO bypass vulnerabilities CVE-2025-59718 and CVE-2025-59719 [CWE-347: Improper Verification of Cryptographic Signature]. CVE-2025-59718 and CVE-2025-59719 affect FortiOS, FortiWeb, FortiProxy, and FortiSwitch Manager, and allow malicious actors to bypass the SSO login authentication via a crafted Security Assertion Markup Language (SAML) message.

Read more…
Source: U.S. Cybersecurity and Infrastructure Security Agency


Sign up for the Cyber Security Review Newsletter
The latest cyber security news and insights delivered right to your inbox


Related:

  • Oracle Releases Biggest Update Ever: 308 Vulnerabilities Patched

    July 18, 2017

    Oracle admins are today staring down the barrel of the biggest quarterly Critical Patch Update ever. The numbers are gory: 308 vulnerabilities patched, 165 of which are remotely exploitable, across more than 90 products. So far in 2017, Oracle has patched 878 vulnerabilities through three CPUs. System and network admins have never been taxed from a patching ...

  • Remotely Exploitable Flaw Puts Millions of Internet-Connected Devices at Risk

    July 18, 2017

    Security researchers have discovered a critical remotely exploitable vulnerability in an open-source software development library used by major manufacturers of the Internet-of-Thing devices that eventually left millions of devices vulnerable to hacking. The vulnerability (CVE-2017-9765), discovered by researchers at the IoT-focused security firm Senrio, resides in the software development library called gSOAP toolkit (Simple Object Access ...

  • Critical RCE Vulnerability Found in Cisco WebEx Extensions, Again — Patch Now!

    July 17, 2017

    A highly critical vulnerability has been discovered in the Cisco Systems’ WebEx browser extension for Chrome and Firefox, for the second time in this year, which could allow attackers to remotely execute malicious code on a victim’s computer. Cisco WebEx is a popular communication tool for online events, including meetings, webinars and video conferences that help ...

  • Siemens Patches Authentication Bypass Flaw in SiPass Server

    July 14, 2017

    A handful of vulnerabilities in Siemens’ SiPass integrated server have been patched, including one that allows an attacker to bypass authentication on the box. SiPass is the company’s integrated access control server managing physical access in a number of industries and use cases. The product supports card readers and integrates with video surveillance equipment, among other ...

  • Hackers are using this new attack method to target power companies

    July 10, 2017

    Phishing emails, used to steal credentials from critical infrastructure firms, can silently harvest data without even using macros, researchers have warned. Hackers are targeting energy companies, including those working in nuclear power and other critical infrastructures providers, with a technique that puts a new spin on a tried-and-tested form of cyberattack. Phishing has long been a successful ...

  • Intel AMT bug bit Siemens industrial PCs

    July 3, 2017

    You don’t need state-sponsored hackers to crack industrial control systems, just an empty Intel AMT login – something Siemens started patching against last week. The bug in Intel’s Active Management Technology emerged in June. It allowed a user to exploit AMT features with an empty login string, and has been shipping in processors since 2010. In Siemens’s ...