Is CVE-2026-24858 actively exploited?

Yes. KEV Intelligence tracks CVE-2026-24858 as a known exploited vulnerability. Confidence is confirmed.

What exploitation activity has KEV Intelligence observed?

KEV Intelligence has not yet recorded sensor-observed exploitation attempts for CVE-2026-24858. Our sensors continue to monitor for activity targeting this CVE.

Which versions are affected?

CVE-2026-24858 affects Fortinet FortiWeb and 5 other products. KEV Intelligence lists 21 version rows; examples include 0 to < *, 8.0.0 to <= 8.0.3, and 7.6.0 to <= 7.6.6.

Yes. CVE-2026-24858 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. KEV Intelligence attested it 1 day ahead of CISA.

Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2026-24858

Q: How should organizations remediate it?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Q: Is it in CISA KEV?

Yes. CVE-2026-24858 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. KEV Intelligence attested it 1 day ahead of CISA.

FortiWeb Authentication Bypass

Fortinet / FortiWeb · affected before *

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Severity: CVSS 9.4 · Critical
Confidence: Confirmed
Exploit status: Exploited in the wild
EPSS: 85.8%
First observed: —
Last observed: —

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-24858 is an unauthenticated vulnerability affecting Fortinet FortiWeb and 5 other products. An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] vulnerability in Fortinet...

Is it exploited?

Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.

Who is affected?

Fortinet / FortiWeb affected before *.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

FortiWeb Authentication Bypass

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.

Vendor Product Affected Status

Siemens RUGGEDCOM APE1808 Before * Affected

Fortinet FortiWeb Through 8.0.3 Affected

Fortinet FortiWeb Through 7.6.6 Affected

Fortinet FortiWeb Through 7.4.11 Affected

Fortinet FortiNAC-F Through 7.6.5 Affected

Fortinet FortiOS Through 7.6.5 Affected

Fortinet FortiOS Through 7.4.10 Affected

Fortinet FortiOS Through 7.2.12 Affected

Fortinet FortiOS Through 7.0.18 Affected

Fortinet FortiAnalyzer Through 7.6.5 Affected

Fortinet FortiAnalyzer Through 7.4.9 Affected

Fortinet FortiAnalyzer Through 7.2.11 Affected

Fortinet FortiAnalyzer Through 7.0.15 Affected

Fortinet FortiProxy Through 7.6.4 Affected

Fortinet FortiProxy Through 7.4.12 Affected

Fortinet FortiProxy Through 7.2.15 Affected

Fortinet FortiProxy Through 7.0.22 Affected

Fortinet FortiManager Through 7.6.5 Affected

Fortinet FortiManager Through 7.4.9 Affected

Fortinet FortiManager Through 7.2.11 Affected

Fortinet FortiManager Through 7.0.15 Affected

Published: 27 Jan 2026
Exploitation Reported: 01 Jun 2026
Attack vector: Remote
Complexity: Low
Privileges: None
User interaction: None

CVE References

https://fortiguard.fortinet.com/psirt/FG-IR-26-060 fortiguard.fortinet.com · CVE Record https://fortiguard.fortinet.com/psirt/FG-IR-26-060

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CVE

Recorded 01 Jun 2026

Independent exploitation attestation added to the KEV Intelligence record.

Proof of concept available

GitHub

Recorded 30 Jan 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

Learn about Pro API access

Source	Added
CVE First	2026-06-01 10:49 UTC
CISA	2026-06-02 14:03 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets: 0
User-Agents: 0

Raw values available in Pro and Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

9.4 Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C

EPSS

85.8%

Weaknesses

Authentication Bypass Using an Alternate Path or Channel CWE-288

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

SimoesCTT/-CTT-NSP-Convergent-Time-Theory---Network-Stack-Projection-CVE-2026-24858-

github · Created 2026-01-30 04:27:24 UTC · 0 stars

A Proof-of-Concept demonstrating the application of 3D Navier-Stokes CTT formulations to packet flow optimization and defensive bypass.

absholi7ly/CVE-2026-24858-FortiCloud-SSO-Authentication-Bypass

github · Created 2026-01-30 03:29:04 UTC · 7 stars

CVE-2026-24858 FortiCloud Single Sign On (SSO) a factory default enabled feature once you register any FortiGate/FortiManager/FortiAnalyzer contains a critical authentication bypass flaw.

m0d0ri205/CVE-2026-24858

github · Created 2026-01-28 14:34:50 UTC · 0 stars

아직 제로데이인거 같아, 공개되거나 천천히 분석할 예정....

Timeline

From disclosure to observed exploitation

02 Jun 2026
Added to CISA KEV

Listed in the CISA Known Exploited Vulnerabilities catalog
01 Jun 2026
Added to KEV Intelligence KEV Feed

High-confidence, third-party attested exploitation
28 Jan 2026
Public PoC available

Public proof-of-concept code published
27 Jan 2026
CVE published

Vulnerability disclosed publicly
27 Jan 2026
CVE ID reserved

Identifier reserved by the CNA

Pro API

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Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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Evidence confidence and provenance
First-party sensor telemetry
PoC and scanner references
Affected versions and enrichment
Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-24858

Free JSON includes basic KEV fields

{
  "cve_id": "CVE-2026-24858",
  "confidence": "Confirmed",
  "cvss_score": 9.4,
  "epss_score": 0.85844,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

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CVE-2026-24858

FortiWeb Authentication Bypass

Tags

CVE References

Exploited in the wild

Proof of concept available

Known exploited vulnerability sources

Observed signals

Scanner coverage

Virtual patch status

Weaknesses

Potential Proof of Concepts

Added to CISA KEV

Added to KEV Intelligence KEV Feed

Public PoC available

CVE published

CVE ID reserved

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