CVE-2026-24858 CISA KEV — actively exploited

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

Fortinet — FortiWeb

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.

CVSS scoreCritical

9.4

EPSS — exploitation probabilityHigh

85.8%

Vector breakdown

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

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

Published: Jan 27, 2026
Modified: Jun 9, 2026
Added to KEV: Jan 27, 2026
Federal patch due: Jan 30, 2026

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.

Weakness classification

CWE-288Authentication Bypass Using an Alternate Path or Channel

Proof-of-concept & exploitation references

Weaponization

Nuclei template

Not found

Metasploit module

Not found

Public repositories whose name or description references CVE-2026-24858, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.

No public GitHub repositories referencing CVE-2026-24858 were found at last check. Absence here is not proof no exploit exists - see the references below for vendor advisories and write-ups.

References

fortiguard.fortinet.com

Frequently asked questions

What is CVE-2026-24858?

How severe is CVE-2026-24858?

CVE-2026-24858 has a CVSS base score of 9.4 out of 10 (CVSS 3.1).

Is CVE-2026-24858 actively exploited in the wild?

Yes. CVE-2026-24858 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Jan 27, 2026, meaning CISA has confirmed evidence of active exploitation.

What is the EPSS score for CVE-2026-24858?

85.8% - meaning FIRST.org's EPSS model estimates a 85.8% probability this vulnerability will be exploited in the wild within 30 days (100% percentile among all scored CVEs).

What type of vulnerability is CVE-2026-24858?

CVE-2026-24858 is classified under CWE-288 (Improper access control).

Cross-checked against

Impactr finds and proves whether CVE-2026-24858 - or flaws like it - are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.

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