9.8

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

CVSS: 9.8v3.1CriticalKEVAnalyzed
Published 27-01-2026Last modified 09-06-2026
Open JSON

Vulnerability summary

CVE-2026-24858 is a critical (CVSS 9.8) vulnerability in Fortinet Multiple Products. It is known to be exploited: CISA lists it, first on 27-01-2026. EPSS estimates a 85.80% chance of exploitation in the next 30 days, higher than 99.7% of scored vulnerabilities.

Overall risk
85/100
0100
Critical · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
85.80%
0%100%
Critical · -0.29 pp in 30 days
KEVListedCISA
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 27-01-2026
    PublishedVulnerability first disclosed.
  2. 27-01-2026
    Added to CISA KEVFortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability
  3. 30-01-2026
    CISA remediation dueApply mitigations per vendor instructions.
  4. 09-06-2026
    Last modifiedVulnerability information updated.

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 metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

85.80%

Chance of exploitation in the next 30 days

Percentile

100%

Versus all other CVEs

30-day change

-0.29 pp

From 86.09% on 21-09-2026

21-09-202621-10-2026
EPSS score
85.80%

Known exploited

Compare KEV catalogs
CISA KEVListed
Added
27-01-2026
Federal due date
30-01-2026

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. www.fortinet.com/blog/psirt-blogs/analysis-of-sso-abuse-on-fortios nvd.nist.gov/vuln/detail/CVE-2026-24858

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Fortinet6 products
  • fortianalyzer≥ 7.6.0, ≤ 7.6.5 | ≥ 7.4.0, ≤ 7.4.9 | ≥ 7.0.0, ≤ 7.0.15 | ≥ 7.2.0, ≤ 7.2.11 | ≥ 7.4.0, < 7.4.10 | ≥ 7.6.0, < 7.6.6
  • fortimanager≥ 7.6.0, ≤ 7.6.5 | ≥ 7.4.0, ≤ 7.4.9 | ≥ 7.0.0, ≤ 7.0.15 | ≥ 7.2.0, ≤ 7.2.11 | ≥ 7.4.0, < 7.4.10 | ≥ 7.6.0, < 7.6.6
  • fortinac-f≥ 7.6.3, ≤ 7.6.5 | ≥ 7.6.3, < 7.6.6
  • fortios≥ 7.6.0, ≤ 7.6.5 | ≥ 7.4.0, ≤ 7.4.10 | ≥ 7.0.0, ≤ 7.0.18 | ≥ 7.2.0, ≤ 7.2.12 | ≥ 7.4.0, < 7.4.11 | ≥ 7.6.0, < 7.6.6
  • 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
Siemens1 product

2 vendors · 7 products

References

4 links