OfficialCISA Known Exploited Vulnerabilities
Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel VulnerabilityType Vulnerability
Fortinet · Auth bypass
Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability
2 sourcesCVE-2026-24858
At a glance
Medium
7-day window, from the last update
ActiveConfirmed in-the-wild exploitation
Evidence-weighted, not popularity
Signal
Actively exploited in the wild — prioritise confirming exposure.
Why Medium
Medium rather than High: exposure is scored at a default because we cannot see your systems or suppliers. If you run or depend on Fortinet FortiWeb, treat it as High.
Briefing
- Do not treat uncorroborated claims as confirmed breaches.
Questions to ask IT
- Do we run Fortinet FortiWeb and FortiOS, and which versions?
- Is any of it reachable from the internet?
- Have we checked whether it has already been used against us?
- If it is not yet patched, what mitigation is in place, and will the fix be done by 12 Nov?
Next steps
- Confirm exposure and remediation status for affected products
Vulnerability facts
Full CVE detail CVE-2026-24858- 9.8 · CriticalExploitable over the network without any account, and no one has to click or open anything. High impact on confidentiality, integrity and availability.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Listed: attacks using it have been seen (on the catalogue since )
- Elevated attack likelihood (~86.6% in 30 days)
- 7.6.5 and earlier, 7.4.9 and earlier, 7.2.11 and earlier, 7.0.15 and earlier, 7.4.10 and earlier, 7.2.12 and earlier, 7.0.18 and earlier, 7.6.4 and earlier, 7.4.12 and earlier, 7.2.15 and earlier, 7.0.22 and earlier, 8.0.3 and earlier, 7.6.6 and earlier, 7.4.11 and earlier
No technical write-up beyond these facts and the summary below yet.
Next steps
- Confirm whether affected products/versions are present and prioritise patching or mitigations
Summary
- CVE-2026-24858 has an estimated attack likelihood score of 0.858 (~85.8% estimated chance of exploitation in the next 30 days; 99.7th percentile) as of 2026-09-24. This is a probability signal from FIRST, not confirmed exploitation.
- CVE-2026-24858 is confirmed as exploited in the wild (US known-exploited catalogue)
- Authoritative catalogues report active exploitation of this vulnerability.
Products and services involved
- Fortinet FortiWeb93% match confidence · CVE-2026-24858
- FortiOS93% match confidence · CVE-2026-24858
Same event, different frames
Distinct often headline the same incident differently.
OfficialFIRST EPSS
CVE-2026-24858: elevated exploitation probabilityPulse
Last checked 3d ago · Recheck overdue since 6 Nov 2026, 08:03 UK time · 1 quiet check collapsed
Update
5 Nov 2026, 08:03 UK time · 3d ago
Suggested changed to 7d.
Listed on the — prioritise confirming exposure and patching.
Drag to pan · Ctrl / ⌘ + scroll or pinch to zoom10 events
2 quiet checks hidden.
Sources
Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability
CVE-2026-24858: elevated exploitation probability
How we know
Statements extracted from sources. Higher confidence means stronger corroboration.
- ClaimedHeadline60% confidence
Fortinet Multiple Products Authentication Bypass Using an Alternate Path or Channel Vulnerability
- ProbableSummary fact75% confidence
CVE-2026-24858 has an estimated attack likelihood score of 0.858 (~85.8% estimated chance of exploitation in the next 30 days; 99.7th percentile) as of 2026-09-24. This is a probability signal from FIRST, not confirmed exploitation.
- ConfirmedCVE identifier95% confidence
Event involves CVE-2026-24858
- ConfirmedKnown-exploited catalogue98% confidence
CVE-2026-24858 is confirmed as exploited in the wild (US known-exploited catalogue)