Actively exploited
Listed in CISA’s Known Exploited Vulnerabilities catalog since January 27, 2026.
CVE-2026-24858
Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability
Added to KEV January 27, 2026
Alert details
- Source feed
- CISA KEV
- CVE ID
- CVE-2026-24858
- CWE
- CWE-288
- Affected products
- Multiple Products · Fortinet Multiple Products · Fortinet
What happened
Fortinet FortiAnalyzer, FortiManager, FortiOS, and FortiProxy contain an authentication bypass using an alternate path or channel that could 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.
What it means for your business
Fortinet Multiple Products is listed in CISA's Known Exploited Vulnerabilities catalog (CVE-2026-24858). Fortinet FortiAnalyzer, FortiManager, FortiOS, and FortiProxy contain an authentication bypass using an alternate path or channel that could 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. CISA remediation due date: 2026-01-30. If you need help checking exposure, call (864) 335-9223.
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.
CISA due date: January 30, 2026
Sources
Related briefs
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Heap buffer overflow in ANGLE in Microsoft Edge vulnerability
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