CVE-2021-26088

CRITICAL

9.6

CVSS Score

Published: July 12, 2021 at 01:21 PM UTC

Updated: June 17, 2026 at 03:42 AM UTC

1 product affected across 1 vendorFortinet Single Sign on

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Severity

CRITICAL9.6

Exploit prediction

EPSS 1%

SSVC

No known exploit

Description

An improper authentication vulnerability in FSSO Collector version 5.0.295 and below may allow an unauthenticated user to bypass a FSSO firewall policy and access the protected network via sending specifically crafted UDP login notification packets.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Fortinet Single Sign on · Fortinet

95%

v < 6.4.67.0.0 ≤ v < 7.0.1FSSO Windows DC Agent 5.0.295, 5.0.294; FSSO Windows CA 5.0.295, 5.0.294

Affected range stops below 6.4.6, so it looks safe — our inference, not a vendor statement

Affected range stops below 7.0.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://fortiguard.com/advisory/FG-IR-20-191

References (1)

x_refsource_CONFIRMVendor Advisory

Source: [email protected]

https://fortiguard.com/advisory/FG-IR-20-191

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

9.6CRITICAL[email protected]

Attack Vector: ADJACENT_NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: CHANGED
Confidentiality: HIGH
Integrity: HIGH
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-287

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