Background exploitation KEV catalog No authentication

CVE-2026-24858

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

CheckOps priority index

8.8/10 Patch within 24 h

Severity9.4

Probability8.7

Exploitation4/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 86.6% higher than 99.7% of CVEs

CVSS 3.1 9.4 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:

Exploited for 280 days 27 Jan 2026

CISA due date 30 Jan 2026 for US federal agencies

Exploitation probability EPSS · FIRST

EPSS probability (%)Percentile among all CVEs

Exploitation signals 4 / 5

KEV catalog (CISA)27 Jan 2026
Exploited in EUVD (ENISA)27 Jan 2026
Used by ransomwareno
EPSS above 10 %86.6%
No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

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.

Affected products

FortiOSFortiAnalyzerFortiProxyFortiWebFortiNAC-FFortiManagerMultiple Products

Affected versions

7.6.0 ≤7.6.5
7.6.0 ≤7.6.4
7.6.0 ≤7.6.6
7.6.3 ≤7.6.5
8.0.0 ≤8.0.3
7.0.0 ≤7.0.18
7.2.0 ≤7.2.11
7.4.0 ≤7.4.11
7.0.0 ≤7.0.15
7.2.0 ≤7.2.12
7.4.0 ≤7.4.12
7.0.0 ≤7.0.22

Weaknesses (CWE)

CWE-288

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

27 Jan 2026
Published
27 Jan 2026
Exploitation reported (ENISA)
27 Jan 2026
Added to the KEV catalog
30 Jan 2026
CISA remediation due date
25 Oct 2026
EPSS peak: 86.6%

References

Other exploited vulnerabilities from the same vendor

CVE-2025-61624Fortinet Multiple Products Path Traversal Vulnerability
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CVE-2026-104286Fortinet FortiMail Path Traversal Vulnerability
5.9 · Actively exploited
CVE-2025-25249Fortinet Multiple Products Heap-based Buffer Overflow Vulnerability
4.9 · Actively exploited
CVE-2025-68686Fortinet FortiOS Exposure of Sensitive Information to an Unauthorized Actor Vulnerability
5.4 · Actively exploited
CVE-2026-39808Fortinet FortiSandbox OS Command Injection Vulnerability
8.8 · Actively exploited
CVE-2026-25089Fortinet FortiSandbox OS Command Injection Vulnerability
8.3 · Actively exploited