CVE-2021-26091
7.5 · HIGHOverview
CVE-2021-26091 is a high-severity vulnerability affecting fortinet fortimail. It was published on March 24, 2025 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
A use of a cryptographically weak pseudo-random number generator vulnerability in the authenticator of the Identity Based Encryption service of FortiMail 6.4.0 through 6.4.4, and 6.2.0 through 6.2.7 may allow an unauthenticated attacker to infer parts of users authentication tokens and reset their credentials.
Remediation
Check the references section for vendor advisories and patches from fortinet. Update fortimail to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| fortinet | fortimail | >= 6.2.0, < 6.4.5 | Affected |
References
Frequently Asked Questions
What is CVE-2021-26091?
CVE-2021-26091 is a high-severity vulnerability affecting fortinet fortimail. It was published on March 24, 2025 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2021-26091?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-26091?
Check the references section for vendor advisories and patches from fortinet. Update fortimail to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-26091?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-26091 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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Browser-based exploitation validates findings with real proof-of-concept.
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