CVE-2026-22153 is a high-severity vulnerability affecting Fortinet FortiOS versions 7.6.0 through 7.6.4. This vulnerability allowsunauthenticated attackers to bypass LDAP authentication under specific configurations of the remote LDAP server. The vulnerability is classified as an Authentication Bypass by Primary Weakness (CWE-305).
The CVSS score for this vulnerability is 8.1, indicating a high level of severity. The combination of high attack vector and impact to confidentiality, integrity, and availability makes this vulnerability particularly concerning for organizations utilizing FortiOS.
Risk to organizations includes potential unauthorized access to sensitive data through bypassing authentication mechanisms. Organizations should prioritize patching immediately.
Currently, there are no known exploits or public proof-of-concept available for this vulnerability. However, the exploitability is rated as high, indicating a significant risk if left unaddressed.
Vulnerability Details
The vulnerability in question allows an attacker to bypass LDAP authentication for Agentless VPN or FSSO policy when the remote LDAP server is configured in a specific way. It is essential to note that all versions of FortiOS prior to the vendor's patch are affected.
The vulnerability has a CVSS score of 8.1, indicating a high severity risk. The attack vector is classified as NETWORK, while the attack complexity is rated as HIGH. There are no privileges required and no user interaction needed to exploit this vulnerability.
Technical Analysis
The root cause of CVE-2026-22153 stems from improper handling of LDAP authentication requests when specific configurations are applied. The attack vector is network-based, allowing potential exploitation from remote locations.
Given the high complexity of the attack and the lack of necessary privileges or user interaction, the vulnerability poses a serious risk. The impacts are severe, potentially leading to unauthorized access to sensitive resources, with high confidentiality, integrity, and availability impacts.
Risk & Impact Analysis
Organizations running affected versions of FortiOS face substantial risks, including unauthorized access to sensitive data and disruption of services. The potential blast radius is significant, as attackers could exploit the vulnerability to gain a foothold in critical systems.
The urgency for remediation is high given the CVSS score of 8.1 and the potential for exploitation. Organizations should address this vulnerability in their priority patch cycle to mitigate any potential risks.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
Fortinet FortiOS versions 7.6.0 through 7.6.4 are affected by this vulnerability. Organizations should ensure their systems are updated to the latest version to mitigate the risk.
Mitigation & Remediation
Fortinet has released patches for this vulnerability. Organizations should prioritize upgrading to FortiOS version 7.6.5 or later. For those unable to patch immediately, it is recommended to implement configuration hardening and restrict access to vulnerable components.
Detection Guidance
Monitoring for unauthorized access attempts and reviewing logs related to LDAP authentication can help detect potential exploitation of this vulnerability.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2026-22153 highlights the critical need for organizations to assess their authentication mechanisms regularly. This vulnerability represents a broader trend in the importance of secure configurations, particularly regarding network-accessible services.
Security teams should continuously evaluate their systems for vulnerabilities to prevent unauthorized access. Implementing robust security measures, including penetration testing, is essential for mitigating risks associated with vulnerabilities like CVE-2026-22153.
For further insights into establishing a secure environment, refer to our penetration testing services that can help identify and remediate vulnerabilities.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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