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:

  • McAfee Bug Can Be Exploited to Gain Windows SYSTEM Privileges

    January 21, 2022

    McAfee has patched two high-severity vulnerabilities in a component of its McAfee Enterprise product that attackers can use to escalate privileges, including up to SYSTEM. According to McAfee’s bulletin, the bugs are in versions prior to 5.7.5 of McAfee Agent, which is used in McAfee Endpoint Security, among other McAfee products. The Agent is the piece of ...

  • Critical Cisco Contact Center Bug Threatens Customer-Service Havoc

    January 14, 2022

    Cisco UCCE is an on-premises customer-service platform capable of supporting up to 24,000 customer-service agents using channels that include inbound voice, outbound voice, outbound interactive voice response (IVR) and digital channels. It also offers a feedback loop via post-call IVR, email and web intercept surveys; and various reporting options to gather information on agent performance ...

  • Analyzing an Old Bug and Discovering CVE-2021-30995

    January 14, 2022

    On April 26, 2021 Apple patched CVE-2021-1740, which was a vulnerable function inside the system daemon process cfprefsd (these types of processes usually run in the background and handle system tasks). The bug could have been exploited to read arbitrary files, write arbitrary files, and get root privilege escalation. It was addressed in Apple’s Security ...

  • Microsoft starts 2022 with big bundle fixes for 96 security bugs in its software

    January 12, 2022

    The new year brings the same old chore of shoring up Microsoft software. For its first Patch Tuesday of 2022, Redmond has bestowed 96 new CVEs affecting its Windows products. If you include 24 Chromium CVEs published earlier this month and now addressed in Microsoft’s Edge browser, in addition to two CVEs in open source projects ...

  • noPac Exploit: Latest Microsoft AD Flaw May Lead to Total Domain Compromise in Seconds

    January 11, 2022

    Microsoft recently published two critical CVEs related to Active Directory (CVE-2021-42278 and CVE-2021-42287), which when combined by a malicious actor could lead to privilege escalation with a direct path to a compromised domain. In mid-December 2021, a public exploit that combined these two Microsoft Active Directory design flaws (referred also as “noPac”) was released. The exploit ...

  • Millions of Routers Exposed to RCE by USB Kernel Bug

    January 11, 2022

    Millions of popular end-user routers are at risk of remote code execution (RCE) due to a high-severity flaw in the KCodes NetUSB kernel module. The module enables remote devices to connect to routers over IP and access any USB devices (such as printers, speakers, webcams, flash drives and other peripherals) that are plugged into them. This ...