CVE-2021-26095

Name: CVE-2021-26095
Creator: NVD / NIST
Published: 2021-07-20T11:15:11.477+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 0.69%

Last modified Jun 17, 2026

CVE-2021-26095 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. The combination of various cryptographic issues in the session management of FortiMail 6.4.0 through 6.4.4 and 6.2.0 through 6.2.6, including the encryption construction of the session cookie, may allow a remote attacker already in possession of a cookie to possibly reveal and alter or forge its content, thereby escalating privileges.. EPSS estimates a 0.69% chance of exploitation in the next 30 days.

Description

The combination of various cryptographic issues in the session management of FortiMail 6.4.0 through 6.4.4 and 6.2.0 through 6.2.6, including the encryption construction of the session cookie, may allow a remote attacker already in possession of a cookie to possibly reveal and alter or forge its content, thereby escalating privileges.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.69%

48.1th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Fortinet	Fortimail	>= 6.2.0, <= 6.2.6
Fortinet	Fortimail	>= 6.4.0, < 6.4.5

References

https://fortiguard.com/advisory/FG-IR-21-019Vendor Advisory
https://fortiguard.com/advisory/FG-IR-21-019Vendor Advisory

Timeline

Published: Jul 20, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-26095?

How severe is CVE-2021-26095?

CVE-2021-26095 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.69% probability of exploitation in the next 30 days.

How do I fix CVE-2021-26095?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-26095?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST