SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-26095

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…

HIGH 8.8EPSS 0.69%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.69%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.69% probability · 53th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Affected
fortinet/fortimail
Source
psirt@fortinet.com
EPSS trend
0%3%5%26 October 2026: 0.69%26 October 202626 October 2026

EPSS 0.7% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.