vciy

CVE-2018-8340

INDEX BUILT · 2026-09-20

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A security feature bypass vulnerability exists when Active Directory Federation Services (AD FS) improperly handles multi-factor authentication…

CVE-2018-83404 of 4 sources documented this
24

rank 24 = 2 + 16 + 1 + 5 + 0

rank@v1 · backlog

Someone is already using it

CISA KEV catalog · public proof-of-concept · FIRST EPSS

EPSS 0.07584  ·  without this subject the record ranks 22

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 6.5, from NVD  ·  without this subject the record ranks 8

It is getting worse, not staying still

FIRST EPSS series, rescorings and bad loads removed

rose on 2026-05-07  ·  without this subject the record ranks 23

How much of the world it touches

NVD CPE configurations

3 products in the CPE ranges  ·  without this subject the record ranks 19

Someone else already set the date

CISA KEV remediation due date

no CISA due date  ·  without this subject the record ranks 24

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$232,000over the next 30 days, if this record is yours
Movement+$145,000on 2025-08-09, the last material move, 1 year before this reading
Basisassumeda published average, not your estate

$232,000 = $4.99M incident cost x 0.6121449559255632 exposure x 0.07584 likelihood

udv@v1 · unaudited · wrong for you until you say what you run

$4.99M is the cost of a breach that happened, from IBM Cost of a Data Breach Report 2026, global average. It is not the value of any asset of yours. That average already covers breaches of every severity, so scaling it by exposure understates a partial-impact record. That is an assumption, not a measurement. Your own asset value goes in the decision record.

Hindsight · the state

0.07584EPSSNOT IN KEVas of 2026-09-20
Severity6.5 MEDIUMreceipt
Harmpartial impactreceipt
Exploitationnone in held sources
Defenseno fix version held
Movementsteadyreceipt
PLATEAU10Minimal movement since 2026-06-15, 83 days at 0.08, as of 2026-09-06. arc-rules@v1

Foresight · where to check next

No weakness class or product neighbourhood is held for this record, so this index cannot name anywhere to check next. That is an absence in the record, not a finding about the software.

Color is a claim, not decoration:the hostile worldthe defenseno signal

Running Microsoft Windows Server 2016? Check your version

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Record your call

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AcceptDeferPatch by…Not affectedMitigated

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Harm, if it fires from the vector and the weakness

Written for the ticket you're about to file.

Reachnetwork-reachable · low privileges required · no user interaction · low attack complexityreceipt
ImpactComplete confidentiality lossreceipt
Scored fromCVSS v3.0 · NVD's vectorreceipt
Weakness classNo CWE mapping in held sources.

CISA KEV & Federal Remediation Deadline from the record and CISA

The fix, and how long it's been waiting.

Fixed inNo fix version in held sources, as the index stood on 6 Sep 2026.
Patch available sinceNo dated patch-availability record in held sources. The index holds reference URLs without dates and only the current revision of the CVE record, so the day a fix first existed cannot be derived. Only the versions it landed in.

Exploit Status & Known PoCs a ladder, not a score

Current rung: Nothing observed in held sources.

  • RUNG 1Nothing observed in held sources
  • RUNG 2Proof-of-concept published
  • RUNG 3Exploited in the wild · CISA KEV listed
  • RUNG 4Ransomware campaign use known

Authority who says so

CVSS, NVD6.5 MEDIUMreceipt
Exploit probability0.07584 · top 6% of all CVEsreceipt
Blast breadth1 product across 1 vendorderived
Assigned bymicrosoftreceipt
Recorded changes25 · last 19 Sep 2026derived

Affected & Fixed Versions as published

Affected productMicrosoft Windows Server 2016; Microsoft Windows Server 2012 R2; Microsoft Windows 10 Serversreceipt
Published rangesmicrosoft windows server 2012 r2; microsoft windows server 2016 1709; microsoft windows server 2016 1803receipt

A rung lights from a row in the index, never from an assessment. "Held sources" is the true scope of the claim: this index reads the CVE record, NVD, CISA KEV, FIRST's EPSS and public proof-of-concept repositories, and it does not observe attacks.

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What it is stated by the CNA

A security feature bypass vulnerability exists when Active Directory Federation Services (AD FS) improperly handles multi-factor authentication requests, aka "AD FS Security Feature Bypass Vulnerability." This affects Windows Server 2016, Windows Server 2012 R2, Windows 10 Servers. receipt

NVD's analysis a second authority

severity
6.5 CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
affected versions
microsoft windows server 2012 r2; microsoft windows server 2016 1709; microsoft windows server 2016 1803

check it yourself securitytracker.com securityfocus.com portal.msrc.microsoft.com receipt

Dated events

2022-02-04EPSS moved 0.09 to 0.022026-06-15EPSS moved 0.19 to 0.08

Movement the material steps

14 Apr 20210.08756
7 Mar 20230.0014 · scoring model v2023.03.01
17 Mar 20250.10488 · crossed 0.10 · scoring model v2025.03.14
30 Mar 20250.0693 · crossed 0.10
9 Aug 20250.11319 · crossed 0.10
15 Jun 20260.07584 · crossed 0.10 · scoring model v2026.06.15
6 Sep 20260.07584
Show all 25 observations
14 Apr 20210.08756
4 Feb 20220.02391
7 Mar 20230.0014
8 Mar 20230.00140
9 Aug 20230.00142
6 Jan 20240.00117
3 Apr 20240.00123
30 May 20240.00104
17 Dec 20240.00098
17 Mar 20250.10488
29 Mar 20250.1535
30 Mar 20250.0693
31 May 20250.06808
16 Jul 20250.06571
9 Aug 20250.11319
7 Dec 20250.14628
3 Jan 20260.14518
31 Jan 20260.12755
1 Mar 20260.15224
7 May 20260.19369
15 Jun 20260.07584
23 Aug 20260.0663
30 Aug 20260.07584
5 Sep 20260.0663
6 Sep 20260.07584

25 observations held. A highlighted step crossed a promotion threshold. A step marked with a scoring model moved because the instrument was replaced, not because the vulnerability changed. receipt

The full biography

EPSS 0.07584Published2018-08-15Index as of2026-09-06

The record had been public for 8 years when this index was last written.

Published 2018-08-15 receipt · Index as of 2026-09-06 derived

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What usually comes next

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