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CVE-2026-24858 KEVPublic exploit Critical · 9.8 EPSS 86.6%

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

Fortinet · Multiple Products

Summary

The flaw is an authentication bypass using an alternate path or channel (CWE-288) in multiple Fortinet products, including FortiOS, FortiAnalyzer, FortiManager, FortiProxy, FortiWeb and FortiNAC-F across the affected version ranges. An attacker holding a FortiCloud account and a registered device can log into other devices registered to other accounts, provided FortiCloud SSO authentication is enabled on those targets.

Official description · NVD

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.

Breakdown
74.8 / 100
Exploited
Yes, in CISA KEV
Reports
0
Tactics
4/15

How an attack unfolds

Based on mappings. Select a step to see the evidence.
  1. How attackers get in

  2. What they do

First seen exploited the day it was disclosed. Public exploit code (PoC-in-GitHub) appeared 1 day after disclosure.

  1. DisclosedFirst seen exploitedVulnCheck KEV evidenceAdded to CISA KEVEU database agreesday 0
  2. Public exploit codePoC-in-GitHub+1 day

CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.

techniques

2 , grouped by in kill-chain order, 2 cited passages 2

Initial AccessTA0001

Valid Accounts T1078 Medium also Persistence, Privilege Escalation, Stealth
AI mapping from the description · primary impact

Gains valid access to other accounts' devices

may allow an attacker with a FortiCloud account and a registered device to log into other devices
From the official description (NVD) Original (opens in a new tab) ↗
Exploit Public-Facing Application T1190 Medium
AI mapping from the description · how it is exploited

Exploited via public-facing FortiCloud SSO authentication bypass

may allow an attacker with a FortiCloud account and a registered device to log into other devices
From the official description (NVD) Original (opens in a new tab) ↗

Detection

0 rules for this CVE · 205 general rules for its techniques

Rules for this CVE

0 that reference CVE-2026-24858 directly.

CVE-specific rules are not available in this build. Search SigmaHQ ↗

Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.

What security researchers reported

Not named in any threat report yet

Also mentioned in 50 community threat pulses (AlienVault OTX)

Weaker evidence

Pulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.

References

4 links, grouped by NVD tag
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