CVE-2026-24858FortinetFirewall and VPNJanuary 27, 2026

Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability

Critical 9.8Actively exploited

Description

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.

What to do

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

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Details

Vendor
Fortinet
Product
FortiOS, FortiProxy, FortiManager, FortiAnalyzer
CVE
CVE-2026-24858
Affected versions
FortiWeb 8.0: from 8.0.0 to 8.0.3
FortiWeb 7.6: from 7.6.0 to 7.6.6
FortiWeb 7.4: from 7.4.0 to 7.4.11
FortiNAC-F 7.6: from 7.6.3 to 7.6.5
FortiOS 7.6: from 7.6.0 to 7.6.5
FortiOS 7.4: from 7.4.0 to 7.4.10
FortiOS 7.2: from 7.2.0 to 7.2.12
FortiOS 7.0: from 7.0.0 to 7.0.18
FortiAnalyzer 7.6: from 7.6.0 to 7.6.5
FortiAnalyzer 7.4: from 7.4.0 to 7.4.9
FortiAnalyzer 7.2: from 7.2.0 to 7.2.11
FortiAnalyzer 7.0: from 7.0.0 to 7.0.15
FortiProxy 7.6: from 7.6.0 to 7.6.4
FortiProxy 7.4: from 7.4.0 to 7.4.12
FortiProxy 7.2: from 7.2.0 to 7.2.15
FortiProxy 7.0: from 7.0.0 to 7.0.22
FortiManager 7.6: from 7.6.0 to 7.6.5
FortiManager 7.4: from 7.4.0 to 7.4.9
FortiManager 7.2: from 7.2.0 to 7.2.11
FortiManager 7.0: from 7.0.0 to 7.0.15 (from the advisory and NVD; check the exact builds in the official advisory)
CVSS score
9.8
Actively exploited
Yes, listed in the CISA Known Exploited Vulnerabilities catalog
CISA due date
January 30, 2026 (deadline for US federal agencies: a good benchmark for you too)
Source
CISA KEV – original advisory
Published
January 27, 2026

The description and the recommended action are quoted from the public advisory; severity, exploitation status and affected versions are compiled automatically from public sources and may contain errors. The vendor's original advisory prevails: check it before taking action. This information is provided without warranty and does not replace a professional assessment.

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