⚠ Actively exploited
Added to CISA KEV on 2026-01-27. Federal agencies required to patch by 2026-01-30. Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable..

CVE-2026-24858

CWE-28813 documents10 sources
Severity
9.8CRITICAL
EPSS
2.3%
top 15.38%
CISA KEV
KEV
Added 2026-01-27
Due 2026-01-30
Exploit
No known exploits
Affected products
5
Fortinet FortianalyzerFortinet FortimanagerFortinet Fortios+2 more
Timeline
PublishedJan 27
KEV addedJan 27
KEV dueJan 30
CISA Required Action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

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…

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitability: 3.9 | Impact: 5.9

Affected Packages10 packages

▶NVDfortinet/fortios7.4.0 — 7.4.11+3
▶NVDfortinet/fortimanager7.4.0 — 7.4.10+3
▶NVDfortinet/fortianalyzer7.4.0 — 7.4.10+3
▶CVEListV5fortinet/fortios7.6.0 — 7.6.5+3
▶CVEListV5fortinet/fortiproxy7.6.0 — 7.6.4+3

🔴Vulnerability Details

3
GHSA
GHSA-2x38-48vp-w23x: An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] vulnerability in Fortinet FortiAnalyzer 7↗2026-01-27
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CVEList
CVE-2026-24858: An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] vulnerability in Fortinet FortiAnalyzer 7↗2026-01-27
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VulnCheck
Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability↗2026
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🔍Detection Rules

4
Elastic
FortiGate Administrator Account Creation from Unusual Source↗
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Elastic
FortiGate Overly Permissive Firewall Policy Created↗
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Elastic
FortiGate FortiCloud SSO Login from Unusual Source↗
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Elastic
FortiGate Configuration File Downloaded↗
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📋Vendor Advisories

2
Fortinet
Administrative FortiCloud SSO authentication bypass↗2026-01-27
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CISA
Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability↗2026-01-27
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🕵️Threat Intelligence

2
Bleepingcomputer
Fortinet blocks exploited FortiCloud SSO zero day until patch is ready↗2026-01-27
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Wiz
CVE-2026-24858 Impact, Exploitability, and Mitigation Steps | Wiz↗
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CVE-2026-24858 (CRITICAL CVSS 9.8) | An Authentication Bypass Using an A | cvebase.io