CVE-2021-42761

criticalpriority · track · 40EPSS 0.015 · 74 %ileEURUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

1.47% (74th) EPSS

CVSS 9.8 · critical

Is it mine?

22 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8.5–9.8

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9

v3.19.8criticalAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.18.5highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H/E:P/RL:U/RC:Csecondary · ENISA EU

v3.19criticalCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:Hsecondary · psirt@fortinet.comexploitability 2.2 · impact 6

v3.19criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-384USprimaryCWE-384US

affected products (22)

Products and version ranges known to be affected.

Fortinet FortiWeb≤ 6.4.0 ≤6.4.2enisa_euvdEU
Fortinet FortiWeb≤ 6.0.0 ≤6.0.7enisa_euvdEU
Fortinet FortiWeb≤ 6.3.0 ≤6.3.16enisa_euvdEU
Fortinet FortiWeb≤ 5.8.5 ≤5.8.7enisa_euvdEU
Fortinet FortiWeb≤ 5.8.0 ≤5.8.3enisa_euvdEU
Fortinet FortiWeb≤ 6.2.0 ≤6.2.6enisa_euvdEU
Fortinet FortiWeb≤ 5.6.0 ≤5.6.2enisa_euvdEU
Fortinet FortiWeb≤ 6.1.0 ≤6.1.2enisa_euvdEU
Fortinet FortiWeb≤ 5.9.0 ≤5.9.1enisa_euvdEU
Fortinet FortiWeb≤ 5.7.0 ≤5.7.3enisa_euvdEU
Fortinet Inc. FortiWeb5.6.0 → 5.9.2fstec_bduRU
Fortinet Inc. FortiWeb6.0.0 → 6.0.8fstec_bduRU
Fortinet Inc. FortiWeb6.1.0 → 6.1.3fstec_bduRU
Fortinet Inc. FortiWeb6.2.0 → 6.2.7fstec_bduRU
Fortinet Inc. FortiWeb6.3.0 → 6.3.17fstec_bduRU
Fortinet Inc. FortiWeb6.4.0 → 7.0.0fstec_bduRU
fortinet fortiweb5.6.0 → 5.9.2nvdUScpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:*
fortinet fortiweb6.0.0 → 6.0.8nvdUScpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:*
fortinet fortiweb6.1.0 → 6.1.3nvdUScpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:*
fortinet fortiweb6.2.0 → 6.2.7nvdUScpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:*

showing 20 of 22

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd NVD CVE.org MITRE

published 2023-02-16modified 2026-06-17

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+603 more

references (5)

External citations — patches, advisories, analysis.

scry

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