CVE-2026-24858: Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel, actively exploited

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.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Affected products

Fortinet Fortianalyzer≥ 7.0.0 ≤ 7.0.15 · ≥ 7.2.0 ≤ 7.2.11 · ≥ 7.4.0 < 7.4.10 · ≥ 7.6.0 < 7.6.6

Fortinet Fortimanager≥ 7.0.0 ≤ 7.0.15 · ≥ 7.2.0 ≤ 7.2.11 · ≥ 7.4.0 < 7.4.10 · ≥ 7.6.0 < 7.6.6

Fortinet Fortinac-f≥ 7.6.3 < 7.6.6

Fortinet FortiProxy≥ 7.0.0 ≤ 7.0.22 · ≥ 7.2.0 ≤ 7.2.15 · ≥ 7.4.0 ≤ 7.4.12 · ≥ 7.6.0 ≤ 7.6.4

Fortinet FortiWeb≥ 7.4.0 ≤ 7.4.11 · ≥ 7.6.0 ≤ 7.6.6 · ≥ 8.0.0 ≤ 8.0.3

Fortinet FortiOS≥ 7.0.0 ≤ 7.0.18 · ≥ 7.2.0 ≤ 7.2.12 · ≥ 7.4.0 < 7.4.11 · ≥ 7.6.0 < 7.6.6

Siemens Ruggedcom Ape1808 Firmwareall versions

Remediation

Fixed in

Fortinet Fortianalyzer≥ 7.4.10

Fortinet Fortimanager≥ 7.4.10

Fortinet Fortinac-f≥ 7.6.6

Fortinet FortiOS≥ 7.4.11

Patch & vendor advisories

References

https://cert-portal.siemens.com/productcert/html/ssa-975644.htmlThird Party Advisory
https://fortiguard.fortinet.com/psirt/FG-IR-26-060Vendor 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-fortiosMitigationVendor Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-24858 being actively exploited?

Yes. CVE-2026-24858 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 27 Jan 2026.

How severe is CVE-2026-24858?

CVE-2026-24858 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 85.8% probability of exploitation.

Which products are affected by CVE-2026-24858?

Affected products include Fortinet Fortianalyzer, Fortinet Fortimanager, Fortinet Fortinac-f, Fortinet FortiProxy, Fortinet FortiWeb, and 2 more.

How do I fix CVE-2026-24858?

Upgrade affected software to a fixed version, for example Fortinet Fortianalyzer 7.4.10, Fortinet Fortimanager 7.4.10, Fortinet Fortinac-f 7.6.6 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-24858 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, a risk for it never ranks below high, and the update that fixes it moves to the Emergency patch lane. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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