Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-22153 is a high-severity Authentication Bypass by Primary Weakness (CWE-305) vulnerability in Fortinet Fortios. Its CVSS base score is 8.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 50th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to IA-2 (Identification and Authentication (Organizational Users)) and IA-8 (Identification and Authentication (Non-organizational Users)) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-22153 is an Authentication Bypass by Primary Weakness vulnerability (CWE-305) in Fortinet FortiOS versions 7.6.0 through 7.6.4. The issue affects LDAP authentication for Agentless VPN or FSSO policy when the remote LDAP server is configured in a specific way, potentially allowing unauthenticated attackers to bypass authentication controls. It carries a CVSS v3.1 base score of 8.1 (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating high severity with network accessibility but high attack complexity.
An unauthenticated attacker can exploit this vulnerability over the network without privileges or user interaction, provided the required specific LDAP server configuration exists. Successful exploitation bypasses LDAP authentication, enabling unauthorized access to Agentless VPN or FSSO policies and resulting in high impacts to confidentiality, integrity, and availability.
Mitigation details are available in the Fortinet PSIRT advisory at https://fortiguard.fortinet.com/psirt/FG-IR-25-1052.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-6387
Vulnerability Data
An Authentication Bypass by Primary Weakness vulnerability [CWE-305] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.4 may allow an unauthenticated attacker to bypass LDAP authentication of Agentless VPN or FSSO policy, when the remote LDAP server is configured in a specific…
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- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 5 hardening rules · 3 OS baselines
V6.4.3V7.2.4
Mitigating Controls (NIST 800-53 r5) AI
Requires unique identification and authentication of users, structurally blocking bypass of the mechanism.
Requires unique identification and authentication of non-organizational users, blocking bypass paths.
Enforces approved authorizations so a bypass weakness cannot be exploited to reach resources.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure development practices throughout the SDLC prevent the primary weaknesses that enable authentication bypass.
Strong authentication mechanisms and policy enforcement directly reduce bypass opportunities arising from implementation flaws.
Identifying and recording vulnerabilities catches the primary weaknesses that allow authentication bypass.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect authentication bypass conditions before deployment.
Secure development lifecycle reduces likelihood of introducing bypass flaws during implementation.
Secure coding practices help prevent the primary weakness that enables authentication bypass.
Information access restriction complements authentication by limiting what can be reached even if bypass occurs.
Secure authentication mechanisms directly address bypass risks in the implemented authentication process.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Ubuntu 22.04 (1 rule)
- V-260470 Ubuntu 22.04 LTS, when booted, must require authentication upon booting into single-user and maintenance modes. prevents CWE-305
Ubuntu 24.04 (1 rule)
- V-270675 Ubuntu 24.04 LTS when booted must require authentication upon booting into single-user and maintenance modes. prevents CWE-305