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:

  • F5 fixes two remote code execution flaws in BIG-IP, BIG-IQ

    November 17, 2022

    F5 has released hotfixes for its BIG-IP and BIG-IQ products, addressing two high-severity flaws allowing attackers to perform unauthenticated remote code execution (RCE) on vulnerable endpoints. While these flaws require specific criteria to exist, making them very difficult to exploit, F5 warns that it could lead to a complete compromise of the devices. The first flaw is ...

  • Pilfered Keys: Free App Infected by Malware Steals Keychain Data

    November 16, 2022

    Today, malware spreads easily, infecting computers of various users. Commonly found on filesharing websites, they disguise themselves as normal applications. Users are then enticed to download them to save money on those programs. However, users risk their security in doing so. Free apps that are infected by a trojan will also affect users who download ...

  • CISA and FBI Release Advisory on Iranian Government-Sponsored APT Actors Compromising Federal Network

    November 16, 2022

    Today, CISA and the Federal Bureau of Investigation (FBI) published a joint Cybersecurity Advisory (CSA), Iranian Government-Sponsored APT Actors Compromise Federal Network, Deploy Crypto Miner, Credential Harvester. The CSA provides information on an incident at a Federal Civilian Executive Branch (FCEB) organization in which Iranian government-sponsored APT actors exploited a Log4Shell vulnerability in unpatched VMware ...

  • Electricity/Energy Cybersecurity: Trends & Survey Response

    November 16, 2022

    Trend Micro conducted a study on the state of industrial cybersecurity in the oil and gas, manufacturing, and electricity/energy industries in 2022. Based on the results of a survey of over 900 ICS business and security leaders in the United States, Germany, and Japan, we will discuss the characteristics of each industry, the motivations and ...

  • Cyber vulnerability in networks used by spacecraft, aircraft and energy generation systems

    November 15, 2022

    A major vulnerability in a networking technology widely used in critical infrastructures such as spacecraft, aircraft, energy generation systems and industrial control systems was exposed by researchers at the University of Michigan and NASA. It goes after a network protocol and hardware system called time-triggered ethernet, or TTE, which greatly reduces costs in high-risk settings by ...

  • CISA Has Added One Known Exploited Vulnerability to Catalog   

    November 14, 2022

    CISA has added one new vulnerability to its Known Exploited Vulnerabilities Catalog, based on evidence of active exploitation. This type of vulnerability is a frequent attack vector for malicious cyber actors and pose significant risk to the federal enterprise. Note: To view the newly added vulnerabilities in the catalog, click on the arrow in the “Date ...