Is CVE-2021-42761 being actively exploited?

CVE-2021-42761 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2021-42761?

CVE-2021-42761 has a CVSS 3.1 base score of 9.0 (CRITICAL).

CVE-2021-42761

CRITICAL · CVSS 9.0EPSS 1.5%EU EUVD

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.

Key facts

CVSS score: 9.0 (v3.1)
Severity: CRITICAL
CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-384
EPSS score: 1.5% (73th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2021-29719)
Published: February 16, 2023
NVD last modified: June 17, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2021-29719 in the EU Vulnerability Database. Last updated in EUVD on October 23, 2024.

View on the EU Vulnerability Database

Affected products

fortinet / fortiweb

Certified products that may be affected

3 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

FortiWeb 5.6 - Fortinet, Inc. - FIPS 140 3103 - historical
FortiWeb-3000E/4000E - Fortinet, Inc. - FIPS 140 3104 - historical
Fortinet Fortiweb 5.6 - Fortinet, Inc. - Common Criteria 383-4-425 - archived

References

https://fortiguard.com/psirt/FG-IR-21-214(Vendor Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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