CVE-2025-59718 is a critical vulnerability affecting multiple Fortinet products, including FortiOS, FortiProxy, and FortiSwitchManager. This vulnerability allows unauthenticated attackers to bypass the FortiCloud SSO login authentication via a crafted SAML response message. The CVSS score for this vulnerability is 9.8, indicating its severity and potential impact on organizations.
Risk to organizations includes unauthorized access to sensitive information, as attackers may leverage this vulnerability to gain entry into systems without proper authentication. Given the critical nature of this vulnerability, organizations using affected Fortinet products should prioritize patching immediately.
The vulnerability has been confirmed to be actively exploited, as indicated by its inclusion in the Known Exploited Vulnerabilities (KEV) catalog. Security teams must act swiftly to mitigate this risk and ensure their systems are secured against potential exploitation.
Organizations should address this vulnerability in their priority patch cycle to prevent unauthorized access and potential data breaches.
Vulnerability Details
This vulnerability allows unauthenticated attackers to bypass authentication mechanisms through improper verification of cryptographic signatures in the handling of SAML responses. The affected versions include FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11, FortiOS 7.0.0 through 7.0.17, FortiProxy 7.6.0 through 7.6.3, FortiProxy 7.4.0 through 7.4.10, FortiProxy 7.2.0 through 7.2.14, FortiProxy 7.0.0 through 7.0.21, FortiSwitchManager 7.2.0 through 7.2.6, and FortiSwitchManager 7.0.0 through 7.0.5.
The CVSS score of 9.8 reflects the critical nature of this vulnerability, with high confidentiality, integrity, and availability impacts due to potential unauthorized access.
The vulnerability is classified under CWE-347, indicating issues with improper verification of cryptographic signatures.
Technical Analysis
The root cause of this vulnerability lies in the improper verification of cryptographic signatures within the SAML response handling process. This flaw allows attackers to forge SAML responses and bypass authentication controls.
The attack vector is network-based, requiring low attack complexity with no privileges required or user interaction necessary. The impact on confidentiality, integrity, and availability is high, making this vulnerability especially dangerous.
Risk & Impact Analysis
Real-world deployment of this vulnerability poses significant risks to organizations, particularly those relying on Fortinet products for security and network management. The potential for unauthorized access can lead to data breaches and loss of sensitive information.
The blast radius of this vulnerability is substantial, as many organizations use Fortinet products in critical infrastructure. Urgency assessment based on the CVSS score and its active exploitation status indicates that organizations must act quickly to mitigate this risk.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | Yes |
Ransomware Use | No |
Affected Versions
The affected versions of Fortinet products include:
FortiOS versions 7.6.0 through 7.6.3, 7.4.0 through 7.4.8, 7.2.0 through 7.2.11, and 7.0.0 through 7.0.17; FortiProxy versions 7.6.0 through 7.6.3, 7.4.0 through 7.4.10, 7.2.0 through 7.2.14, and 7.0.0 through 7.0.21; FortiSwitchManager versions 7.2.0 through 7.2.6 and 7.0.0 through 7.0.5.
Mitigation & Remediation
Organizations should apply patches as soon as they are available from Fortinet. The vendor has provided specific remediation steps and updates that must be followed to mitigate this vulnerability. For more comprehensive security, organizations may consider implementing penetration testing and security assessments to evaluate their defenses.
Detection Guidance
To detect potential exploitation attempts, organizations should monitor log indicators for unauthorized SSO login attempts and unusual behavior associated with SAML responses. Additionally, behavioral anomalies in user authentication processes should be investigated.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability reflects a critical gap in authentication mechanisms that can lead to serious security breaches. Security teams must learn from this incident to strengthen SSO implementations and ensure robust cryptographic practices are in place.
This incident highlights the need for continuous security testing and proactive vulnerability management to address weaknesses before they can be exploited. For organizations using Fortinet products, it is essential to remain vigilant and apply updates promptly.
For further reading on security testing best practices, organizations can refer to our penetration testing methodology article.
Known Exploitation Timeline
CVE-2025-59718 was added to the KEV catalog on December 16, 2025, indicating its significance and the urgency for organizations to address it before it can be exploited widely.
Affected Versions
The affected versions of Fortinet products include:
FortiOS versions 7.6.0 through 7.6.3, 7.4.0 through 7.4.8, 7.2.0 through 7.2.11, and 7.0.0 through 7.0.17; FortiProxy versions 7.6.0 through 7.6.3, 7.4.0 through 7.4.10, 7.2.0 through 7.2.14, and 7.0.0 through 7.0.21; FortiSwitchManager versions 7.2.0 through 7.2.6 and 7.0.0 through 7.0.5.
Mitigation & Remediation
Organizations should apply patches as soon as they are available from Fortinet. The vendor has provided specific remediation steps and updates that must be followed to mitigate this vulnerability. For more comprehensive security, organizations may consider implementing penetration testing and security assessments to evaluate their defenses.
Detection Guidance
To detect potential exploitation attempts, organizations should monitor log indicators for unauthorized SSO login attempts and unusual behavior associated with SAML responses. Additionally, behavioral anomalies in user authentication processes should be investigated.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability reflects a critical gap in authentication mechanisms that can lead to serious security breaches. Security teams must learn from this incident to strengthen SSO implementations and ensure robust cryptographic practices are in place.
This incident highlights the need for continuous security testing and proactive vulnerability management to address weaknesses before they can be exploited. For organizations using Fortinet products, it is essential to remain vigilant and apply updates promptly.
For further reading on security testing best practices, organizations can refer to our penetration testing methodology article.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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