SB2026111109 - Format string error in FortiMail
Published: November 11, 2026
Security Bulletin ID
SB2026111109
CSH Severity
High
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Format string error (CVE-ID: CVE-2026-126163)
CWE-ID: CWE-134 - Use of Externally-Controlled Format String
CVSSv4: 9.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.
The vulnerability exists due to use of externally-controlled format string. A remote unauthenticated attacker can execute unauthorized code or commands via a specially crafted SMTP command.
Remediation
Install update from vendor's website.