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:

  • Deep dive into CVE‑2025‑29824 in Windows

    August 19, 2025

    On April 8, 2025, Microsoft patched 121 vulnerabilities across its products, including CVE-2025-29824—the only one known to be exploited in the wild. This particular flaw enabled adversaries to escalate Windows privileges by leveraging a bug in the clfs.sys driver. Microsoft Threat Intelligence discovered the issue during the Storm-2460 attacks targeting organizations in Saudi Arabia, Spain, Venezuela, ...

  • Cisco warns of worrying major security flaw in firewall command center – patch now

    August 18, 2025

    Cisco recently fixed a maximum-severity vulnerability in its Secure Firewall Management Center (FMC) product, and urged users to apply either the patch, or the mitigation, as soon as possible. FMC is a centralized platform for configuring, monitoring, and analyzing Cisco Secure Firewalls, where users can manage policies, track threat intelligence, and monitor their deployments across endpoints. ...

  • Evolution of the PipeMagic backdoor: from the RansomExx incident to CVE-2025-29824

    August 18, 2025

    In April 2025, Microsoft patched 121 vulnerabilities in its products. According to the company, only one of them was being used in real-world attacks at the time the patch was released: CVE-2025-29824. The exploit for this vulnerability was executed by the PipeMagic malware, which Kaspersky researchers first discovered in December 2022 in a RansomExx ransomware campaign. ...

  • Fortinet Releases Security Advisory for Authentication Bypass Vulnerability

    August 12, 2025

    An authentication bypass using an alternate path or channel vulnerability in FortiOS, FortiProxy & FortiPAM may allow an unauthenticated attacker to seize control of a managed device via crafted FGFM requests, if the device is managed by a FortiManager, and if the attacker knows that FortiManager’s serial number. Read more… Source: Fortinet Sign up for the Cyber ...

  • WinRAR vulnerability exploited by two different groups

    August 12, 2025

    On July 30, 2025, WinRAR released a new version (7.13 Final) to patch a vulnerability which was used in two separate malware campaigns. WinRAR is a popular file archiving and data compression tool that allows users to compress files into smaller archives, like RAR and ZIP, and can also unpack various archive formats. The vulnerability, tracked ...

  • Security flaws in a carmaker’s web portal let one hacker remotely unlock cars from anywhere

    August 10, 2025

    A security researcher said flaws in a carmaker’s online dealership portal exposed the private information and vehicle data of its customers, and could have allowed hackers to remotely break into any of its customers’ vehicles. Eaton Zveare, who works as a security researcher at software delivery company Harness, told TechCrunch the flaw he discovered allowed the ...