CVE-2026-24858

Name: CVE-2026-24858
Creator: NVD / NIST
Published: 2026-01-27T20:16:24.477+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10Actively ExploitedEPSS 85.84%

Last modified Jun 17, 2026

CVE-2026-24858 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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, FortiNAC-F 7.6.3 through 7.6.5, 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, FortiProxy 7.6.0 through 7.6.4, FortiProxy 7.4.0 through 7.4.12, FortiProxy 7.2.0 through 7.2.15, FortiProxy 7.0.0 through 7.0.22, FortiWeb 8.0.0 through 8.0.3, FortiWeb 7.6.0 through 7.6.6, FortiWeb 7.4.0 through 7.4.11 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.. CISA has confirmed active exploitation in the wild. EPSS estimates a 85.84% chance of exploitation in the next 30 days.

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, FortiNAC-F 7.6.3 through 7.6.5, 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, FortiProxy 7.6.0 through 7.6.4, FortiProxy 7.4.0 through 7.4.12, FortiProxy 7.2.0 through 7.2.15, FortiProxy 7.0.0 through 7.0.22, FortiWeb 8.0.0 through 8.0.3, FortiWeb 7.6.0 through 7.6.6, FortiWeb 7.4.0 through 7.4.11 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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

85.84%

99.7th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Jan 30, 2026.

Weakness Enumeration

CWE-288

Affected Software

Vendor	Product	Versions
Fortinet	Fortianalyzer	>= 7.0.0, <= 7.0.15
Fortinet	Fortianalyzer	>= 7.2.0, <= 7.2.11
Fortinet	Fortianalyzer	>= 7.4.0, < 7.4.10
Fortinet	Fortianalyzer	>= 7.6.0, < 7.6.6
Fortinet	Fortimanager	>= 7.0.0, <= 7.0.15
Fortinet	Fortimanager	>= 7.2.0, <= 7.2.11
Fortinet	Fortimanager	>= 7.4.0, < 7.4.10
Fortinet	Fortimanager	>= 7.6.0, < 7.6.6
Fortinet	Fortinac-F	>= 7.6.3, < 7.6.6
Fortinet	Fortiproxy	>= 7.0.0, <= 7.0.22
Fortinet	Fortiproxy	>= 7.2.0, <= 7.2.15
Fortinet	Fortiproxy	>= 7.4.0, <= 7.4.12
Fortinet	Fortiproxy	>= 7.6.0, <= 7.6.4
Fortinet	Fortiweb	>= 7.4.0, <= 7.4.11
Fortinet	Fortiweb	>= 7.6.0, <= 7.6.6
Fortinet	Fortiweb	>= 8.0.0, <= 8.0.3
Fortinet	Fortios	>= 7.0.0, <= 7.0.18
Fortinet	Fortios	>= 7.2.0, <= 7.2.12
Fortinet	Fortios	>= 7.4.0, < 7.4.11
Fortinet	Fortios	>= 7.6.0, < 7.6.6
Siemens	Ruggedcom Ape1808 Firmware	All versions

References

https://fortiguard.fortinet.com/psirt/FG-IR-26-060Vendor Advisory
https://cert-portal.siemens.com/productcert/html/ssa-975644.htmlThird Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-24858US Government Resource
https://www.fortinet.com/blog/psirt-blogs/analysis-of-sso-abuse-on-fortiosMitigation, Vendor Advisory

Timeline

Published: Jan 27, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-24858?

How severe is CVE-2026-24858?

CVE-2026-24858 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 85.84% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2026-24858?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-24858?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST