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:

  • New Plundervolt attack impacts Intel CPUs

    December 10, 2019

    Academics from three universities across Europe have disclosed today a new attack that impacts the integrity of data stored inside Intel SGX, a highly-secured area of Intel CPUs. The attack, which researchers have named Plundervolt, exploits the interface through which an operating system can control an Intel processor’s voltage and frequency — the same interface that allows ...

  • OpenBSD Hit with Authentication, LPE Bugs

    December 5, 2019

    An authentication bypass and three local privilege-escalation (LPE) bugs have been uncovered in OpenBSD, the Unix-like open-source operating system known for its security protections. The most severe of the vulnerabilities is the bypass (CVE-2019-19521), which is remotely exploitable. OpenBSD uses BSD authentication, which enables the use of passwords, S/Key challenge-and-response authentication and Yubico YubiKey tokens. In each ...

  • New vulnerability lets attackers sniff or hijack VPN connections

    December 5, 2019

    Academics have disclosed this week a security flaw impacting Linux, Android, macOS, and other Unix-based operating systems that allows an attacker to sniff, hijack, and tamper with VPN-tunneled connections. The vulnerability — tracked as CVE-2019-14899 — resides in the networking stacks of multiple Unix-based operating systems, and more specifically, in how the operating systems reply to ...

  • FBI warns about snoopy smart TVs spying on you

    December 3, 2019

    She laughed. I laughed. The TV laughed. I shot the TV. “Blasted Decepticons!” That’s how a popular meme went after the Transformer movies hit it big. Today, it’s not so funny. A recent FBI report warned smart TV users that hackers can also take control of your unsecured TV. “At the low end of the risk spectrum, they can ...

  • Android: New StrandHogg vulnerability is being exploited in the wild

    December 2, 2019

    Security researchers from Promon, a Norwegian firm specialized in in-app security protections, said they identified a bug in the Android operating system that lets malicious apps hijack legitimate app, and perform malicious operations on their behalf. In a comprehensive report published today, the research team said the vulnerability can be used to trick users into granting intrusive permissions ...

  • Exploit code published for dangerous Apache Solr remote code execution flaw

    November 25, 2019

    Confusion still surrounds a security bug that the Apache Solr team patched over the summer, which turns out it’s actually much more dangerous than anyone thought. Apache Solr is a Java-based open-source search engine, initially developed to add search functionality to the CNET website. The project was donated to the Apache Software Foundation in 2006, from where ...