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:

  • CPU bug patch saga: Antivirus tools caught with their hands in the Windows cookie jar

    January 9, 2018

    Microsoft’s workaround to protect Windows computers from the Intel processor security flaw dubbed Meltdown has revealed the rootkit-like nature of modern security tools. Some anti-malware packages are incompatible with Redmond’s Meltdown patch, released last week, because the tools make, according to Microsoft, “unsupported calls into Windows kernel memory,” crashing the system with a blue screen of death. In extreme ...

  • Triple Meltdown: How So Many Researchers Found A 20-Year-Old Chip Flaw At The Same Time.

    January 7, 2018

    On a cold Sunday early last month in the small Austrian city of Graz, three young researchers sat down in front of the computers in their homes and tried to break their most fundamental security protections. Two days earlier, in their lab at Graz’s University of Technology, Moritz Lipp, Daniel Gruss, and Michael Schwarz had determined to ...

  • Rush to fix ‘serious’ computer chip flaws

    January 4, 2018

    Tech firms are working to fix two bugs that could allow hackers to steal personal data from computer systems. Google researchers said one of the “serious security flaws”, dubbed “Spectre”, was found in chips made by Intel, AMD and ARM. The other, known as “Meltdown” affects Intel-made chips alone. The industry has been aware of the problem for ...

  • Satori IoT botnet malware code given away for Christmas

    January 2, 2018

    A hacker has released the working code for a Huawei router exploit used by the Satori botnet over the holiday season as a freebie for cyberattackers seeking to target Huawei devices or bolster botnets. According to NewSky Security principal researcher Ankit Anubhav, the exploit’s code was released on Pastebin over the holiday season. Read more… Source: ZDNet  

  • Kernel-memory-leaking Intel processor design flaw forces Linux, Windows redesign

    January 2, 2018

    A fundamental design flaw in Intel’s processor chips has forced a significant redesign of the Linux and Windows kernels to defang the chip-level security bug. Programmers are scrambling to overhaul the open-source Linux kernel’s virtual memory system. Meanwhile, Microsoft is expected to publicly introduce the necessary changes to its Windows operating system in an upcoming Patch ...

  • MacOS LPE Exploit Gives Attackers Root Access

    January 2, 2018

    A researcher that goes by the handle “Siguza” released details of a local privilege escalation attack against macOS that dates back to 2002. A successful attack could give adversaries complete root access to targeted systems. Siguza released details of the attack on Dec. 31 via Twitter, wishing followers a “Happy New Year” and linked to a ...