CVE-2026-24858
Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability - [Actively Exploited]
Description
An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] vulnerability in Fortinet FortiAnalyzer 7.6.0 through 7.6.5, FortiAnalyzer 7.4.0 through 7.4.9, FortiAnalyzer 7.2.0 through 7.2.11, FortiAnalyzer 7.0.0 through 7.0.15, FortiManager 7.6.0 through 7.6.5, FortiManager 7.4.0 through 7.4.9, FortiManager 7.2.0 through 7.2.11, FortiManager 7.0.0 through 7.0.15, FortiOS 7.6.0 through 7.6.5, FortiOS 7.4.0 through 7.4.10, FortiOS 7.2.0 through 7.2.12, FortiOS 7.0.0 through 7.0.18 may allow an attacker with a FortiCloud account and a registered device to log into other devices registered to other accounts, if FortiCloud SSO authentication is enabled on those devices.
INFO
Published Date :
Jan. 27, 2026, 8:16 p.m.
Last Modified :
Jan. 27, 2026, 10:15 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CISA KEV (Known Exploited Vulnerabilities)
For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.
Fortinet FortiAnalyzer, FortiManager, FortiOS, and FortiProxy contain an authentication bypass using an alternate path or channel that could allow an attacker with a FortiCloud account and a registered device to log into other devices registered to other accounts, if FortiCloud SSO authentication is enabled on those devices.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Please adhere to Fortinet's guidelines to assess exposure and mitigate risks. Check for signs of potential compromise on all internet accessible Fortinet products affected by this vulnerability. Apply any final mitigations provided by the vendor as soon as they become available. For more information please see: https://fortiguard.fortinet.com/psirt/FG-IR-26-060 ; https://www.fortinet.com/blog/psirt-blogs/analysis-of-sso-abuse-on-fortios ; https://nvd.nist.gov/vuln/detail/CVE-2026-24858
Affected Products
The following products are affected by CVE-2026-24858
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | 6abe59d8-c742-4dff-8ce8-9b0ca1073da8 | ||||
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Update FortiAnalyzer to version 7.6.6 or later.
- Update FortiManager to version 7.6.6 or later.
- Update FortiOS to version 7.6.6 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-24858.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-24858 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-24858
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-24858 vulnerability anywhere in the article.
-
Daily CyberSecurity
Pre-Auth RCE Risk: OpenSSL Patches High-Severity Stack Overflow (CVE-2025-15467)
The maintainers of OpenSSL, the cryptographic library that underpins a vast portion of the secure web, have released a sweeping security update to address a dozen vulnerabilities ranging from memory c ... Read more
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Daily CyberSecurity
Under Attack: Critical Fortinet Auth Bypass (CVE-2026-24858) Exploited in the Wild
Fortinet has issued an urgent warning regarding a critical vulnerability affecting its core network security platforms, including FortiOS, FortiManager, and FortiAnalyzer. The flaw, tracked as CVE-202 ... Read more
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Daily CyberSecurity
Chrome Patches High-Severity Background Fetch Flaw (CVE-2026-1504)
Google has rolled out an important update for the Chrome Stable channel, pushing version 144.0.7559.109/110 to Windows and Mac users (and 144.0.7559.109 for Linux) to address a single, high-severity s ... Read more
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TheCyberThrone
CVE-2026-24858: Fortinet FortiCloud SSO Zero-Day Under Active Exploitation
January 28, 2026A critical authentication bypass vulnerability, CVE-2026-24858, impacts multiple Fortinet products via flawed FortiCloud SSO controls. Fortinet confirmed active exploitation by malicio ... Read more
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Help Net Security
Fortinet starts patching exploited FortiCloud SSO zero-day (CVE-2026-24858)
Fortinet has begun releasing FortiOS versions that fix CVE-2026-24858, a critical zero-day vulnerability that allowed attackers to log into targeted organizations’ FortiGate firewalls. “This vulnerabi ... Read more
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BleepingComputer
Fortinet blocks exploited FortiCloud SSO zero day until patch is ready
Fortinet has confirmed a new, actively exploited critical FortiCloud single sign-on (SSO) authentication bypass vulnerability, tracked as CVE-2026-24858, and says it has mitigated the zero-day attacks ... Read more
The following table lists the changes that have been made to the
CVE-2026-24858 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jan. 27, 2026
Action Type Old Value New Value Added Reference https://www.fortinet.com/blog/psirt-blogs/analysis-of-sso-abuse-on-fortios -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jan. 27, 2026
Action Type Old Value New Value Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-24858 -
New CVE Received by [email protected]
Jan. 27, 2026
Action Type Old Value New Value Added Description An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] vulnerability in Fortinet FortiAnalyzer 7.6.0 through 7.6.5, FortiAnalyzer 7.4.0 through 7.4.9, FortiAnalyzer 7.2.0 through 7.2.11, FortiAnalyzer 7.0.0 through 7.0.15, FortiManager 7.6.0 through 7.6.5, FortiManager 7.4.0 through 7.4.9, FortiManager 7.2.0 through 7.2.11, FortiManager 7.0.0 through 7.0.15, FortiOS 7.6.0 through 7.6.5, FortiOS 7.4.0 through 7.4.10, FortiOS 7.2.0 through 7.2.12, FortiOS 7.0.0 through 7.0.18 may allow an attacker with a FortiCloud account and a registered device to log into other devices registered to other accounts, if FortiCloud SSO authentication is enabled on those devices. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-288 Added Reference https://fortiguard.fortinet.com/psirt/FG-IR-26-060