vciy

CVE-2021-42761

INDEX BUILT · 2026-10-18

No source can show you its own past. This one can.

Print this page to keep the view as it stands on this date. Everything hidden behind a disclosure opens, and every receipt prints with its value.

A condition for session fixation vulnerability [CWE-384] in the session management of FortiWeb versions 6.4 all versions, 6.3.0 through 6.3.16, 6.2.0…

CVE-2021-427614 of 4 sources documented this
31

rank 31 = 0 + 25 + 0 + 6 + 0

rank@v1 · scheduled

Someone is already using it

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

EPSS 0.01465  ·  without this subject the record ranks 31

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 9.8, from NVD  ·  without this subject the record ranks 6

It is getting worse, not staying still

FIRST EPSS series, rescorings and bad loads removed

no persisting rise in 365 days  ·  without this subject the record ranks 31

How much of the world it touches

NVD CPE configurations

6 products in the CPE ranges  ·  without this subject the record ranks 25

Someone else already set the date

CISA KEV remediation due date

no CISA due date  ·  without this subject the record ranks 31

Hindsight · the state

0.01465EPSSNOT IN KEVas of 2026-10-18
Severity8.5 HIGHreceipt
Harmtotal loss · unauthenticatedreceipt
Exploitationnone in held sources
Defenseunaffected versions publishedreceipt
Movementscoring model changedreceipt
PLATEAU10Minimal movement since 2023-02-17, 1214 days at 0.01, as of 2026-06-15. 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

Sources disagree here.

Severity score
Fortinet8.5 HIGHreceipt
NVD9.8 CRITICALreceipt
What it costs
FortinetComplete confidentiality, integrity and availability loss, with impact beyond the vulnerable componentreceipt
NVDComplete confidentiality, integrity and availability lossreceipt

Both shown, dated. We don't pick winners. disagreement-rules@v1

Running Fortinet FortiWeb? Check your version

A deterministic range check against the ranges this record publishes. It tells you where a version sits in the record, not whether your deployment is exploitable. No account needed.

Watch this record

Matches your own product list against every record this index holds, and tells you when one of them moves.

What counts as a move

Watch Fortinet FortiWeb

Set up a watchlist (free with an account: one stack of three products)

Record your call

Keep your verdict, your reason and the evidence together. The record takes its date when you save it.

Patch by…

Or open an investigation: an incident or a near miss on this CVE, kept with its evidence where anyone in your organisation can find it.

Choose your verdict, then sign in or use an email link. Your first 100 records are free. Evidence is frozen when the record is created.

Private to your organization unless you share it. Put the proof link in your ticket so a reviewer can inspect the basis for your call. See how decision records work.

Harm, if it fires from the vector and the weakness

Written for the ticket you're about to file.

Reachnetwork-reachable · no privileges required · no user interaction · high attack complexityreceipt
ImpactComplete confidentiality, integrity and availability loss, with impact beyond the vulnerable componentreceipt
Scored fromCVSS v3.1 · the CNA's vectorreceipt
Weakness classCWE-384 Session Fixationreceipt
Published consequencesCWE-384: Access Control: Gain Privileges or Assume Identitycwe-consequences@4.20

CISA KEV & Federal Remediation Deadline from the record and CISA

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

First unaffected version, by branchfortiweb 5.9.2; fortiweb 6.0.8; fortiweb 6.1.3; fortiweb 6.2.7; fortiweb 6.3.17; fortiweb 7.0.0receipt
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.
BOD 26-04 deadlineIf the system is reachable from the internet: 14 days. If not: fix at the next system upgrade.derived
Show full BOD 26-04 deadline

CISA has not scored it, so the directive's own defaults apply: automatable no, technical impact total. Calendar days from the KEV listing or from when you find it on a system, whichever is first. Federal agencies are bound from 7 Dec 2026, and contracts often carry it to suppliers. The directive and its table

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, the CNA8.5 HIGHreceipt
CVSS, NVD9.8 CRITICALreceipt
Exploit probability0.01465 · top 27% of all CVEsreceipt
Blast breadth1 product across 1 vendorderived
Assigned byfortinetreceipt
Recorded changes23 · last 18 Oct 2026derived

Affected & Fixed Versions as published

Affected productFortinet FortiWebreceipt
Published rangesfortinet fortiweb >= 5.6.0 < 5.9.2; fortinet fortiweb >= 6.0.0 < 6.0.8; fortinet fortiweb >= 6.1.0 < 6.1.3; fortinet fortiweb >= 6.2.0 < 6.2.7receipt
Show all 6 published ranges
fortinet fortiweb >= 5.6.0 < 5.9.2
fortinet fortiweb >= 6.0.0 < 6.0.8
fortinet fortiweb >= 6.1.0 < 6.1.3
fortinet fortiweb >= 6.2.0 < 6.2.7
fortinet fortiweb >= 6.3.0 < 6.3.17
fortinet fortiweb >= 6.4.0 < 7.0.0

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.

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$73,100over the next 30 days, if this record is yours
Movementno material movementthe record holds only daily drift and scoring model releases
Basisassumeda published average, not your estate

$73,100 = $4.99M incident cost x 1 exposure x 0.01465 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.

Did this affect your environment?Answering needs an account.

Attack path

Unauthenticated network requestno credentials, no interactionFortinet FortiWebCWE-384 weaknessAdjacent componentsscope changeFull compromise (C/I/A)C:H / I:H / A:Hexploits CWE-384scope changedata compromise

What it is stated by the CNA

A condition for session fixation vulnerability [CWE-384] in the session management of FortiWeb versions 6.4 all versions, 6.3.0 through 6.3.16, 6.2.0 through 6.2.6, 6.1.0 through 6.1.2, 6.0.0 through 6.0.7, 5.9.0 through 5.9.1 may allow a remote, unauthenticated attacker to infer the session identifier of other users and possibly usurp their session. receipt

NVD's analysis a second authority

severity
9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
weakness
CWE-384
affected versions
fortinet fortiweb >= 5.6.0 < 5.9.2; fortinet fortiweb >= 6.0.0 < 6.0.8; fortinet fortiweb >= 6.1.0 < 6.1.3; and 3 more, listed in full below
also scored by
psirt@fortinet.com 9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

The CNA scored it 8.5 and NVD 9.8. Both are shown because both were published; we do not pick one.

check it yourself fortiguard.com receipt

Movement the material steps

17 Feb 20230.01055
7 Mar 20230.00147 · scoring model v2023.03.01
17 Mar 20250.0251 · scoring model v2025.03.14
15 Jun 20260.01465 · scoring model v2026.06.15
Show all 23 observations
17 Feb 20230.01055
7 Mar 20230.00147
17 Jan 20240.00162
23 Feb 20240.00256
20 Mar 20240.00260
29 Jul 20240.00284
8 Sep 20240.00326
23 Sep 20240.00347
17 Dec 20240.00302
31 Jan 20250.00325
17 Mar 20250.0251
29 Mar 20250.03094
30 Mar 20250.0251
12 Sep 20250.01304
11 Nov 20250.01625
18 Nov 20250.01323
21 Nov 20250.01625
13 Dec 20250.01914
24 Feb 20260.0195
25 Feb 20260.01395
28 Feb 20260.01663
24 Mar 20260.01653
15 Jun 20260.01465

23 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 0.01465Published2023-02-16Index as of2026-06-15

The record had been public for 3 years, 3 months when this index was last written.

Published 2023-02-16 receipt · Index as of 2026-06-15 derived

Siblings and hubs

Records related to this one

Browse the index from here

These are index-wide views, not findings about CVE-2021-42761.

What usually comes next

Everything above needs no account. What is below is work: assembling it, scoping it to your estate, watching it, and handing it to someone else.

Everything on this page is free. Public data. Withholding it protects nothing.