Hazard

Is CVE-2026-24858 being exploited?

Weaponised and widely attempted

Reliable public exploit code exists, or mass exploitation attempts are probable. Patch inside days, not weeks.

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

Fortinet · Multiple Products

CVSS 9.8 EPSS 86% no public exploit indexed Fix deadline passed 30 January 2026

What it is

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.

Why we say that

  • EPSS puts exploitation in the next 30 days at 86%
  • CISA's federal remediation deadline (2026-01-30) has passed
  • CVSS 9.8 critical
  • Listed in the CISA Known Exploited Vulnerabilities catalogue

Every line above comes from a named public source. Where the evidence is thin, we say so rather than inventing confidence — see methodology.

What to do

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

What it costs when this goes wrong

This is where UK enforcement meets the vulnerability record. Where an unfixed vulnerability leads to a breach, the ICO treats it as a security failure under UK GDPR. Recent cases:

All UK cases caused by unpatched software →