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:

  • CVE-2024-20697: Windows Libarchive Remote Code Execution Vulnerability

    April 17, 2024

    An integer overflow vulnerability exists in the Libarchive library included in Microsoft Windows. The vulnerability is due to insufficient bounds checks on the block length of a RARVM filter used for Intel E8 preprocessing, included in the compressed data of a RAR archive. A remote attacker could exploit this vulnerability by enticing a target user into ...

  • Botnets Continue Exploiting CVE-2023-1389 for Wide-Scale Spread

    April 16, 2024

    Last year, a command injection vulnerability, CVE-2023-1389, was disclosed and a fix developed for the web management interface of the TP-Link Archer AX21 (AX1800). FortiGuard Labs has developed an IPS signature to tackle this issue. Recently, their researchers observed multiple attacks focusing on this year-old vulnerability, spotlighting botnets like Moobot, Miori, the Golang-based agent “AGoent,” and ...

  • Trust Wallet Issues Warning to Apple Users About Zero-Day Exploit in iMessage

    April 16, 2024

    Trust Wallet, a popular web3 wallet, has issued a warning to Apple users, urging them to disable iMessage due to “credible intel” regarding a zero-day exploit. The company shared the alert on X, stating that the exploit, which is being sold on the Dark Web, could potentially allow hackers to take control of users’ iPhones without ...

  • “Highly capable” hackers root corporate networks by exploiting Palo Alto Networks firewall 0-day

    April 12, 2024

    Highly capable hackers are rooting multiple corporate networks by exploiting a maximum-severity zero-day vulnerability in a firewall product from Palo Alto Networks, researchers said Friday. The vulnerability, which has been under active exploitation for at least two weeks now, allows the hackers with no authentication to execute malicious code with root privileges, the highest possible level ...

  • Hackable Intel and Lenovo hardware that went undetected for 5 years won’t ever be fixed

    April 11, 2024

    Hardware sold for years by the likes of Intel and Lenovo contains a remotely exploitable vulnerability that will never be fixed. The cause: a supply chain snafu involving an open source software package and hardware from multiple manufacturers that directly or indirectly incorporated it into their products. Researchers from security firm Binarly have confirmed that the ...

  • Microsoft’s April 2024 Patch Tuesday includes two actively exploited zero-day vulnerabilities

    April 11, 2024

    The April 2024 Patch Tuesday update includes patches for 149 Microsoft vulnerabilities and republishes 6 non-Microsoft CVEs. Three of those 149 vulnerabilities are listed as critical, and one is listed as actively exploited by Microsoft. Another vulnerability is claimed to be a zero-day by researchers that have found it to be used in the wild. Let’s ...