Highly exploitable, CVE-2026-40683 poses a critical security risk that could lead to severe breaches.
Status: Awaiting Analysis
Last updated: 🕞 17 Apr 2026, 15:38 UTC
Originally published on: 🕗 14 Apr 2026, 20:16 UTC
Time between publication and last update: 2 days
CVSS Release: version 3
cve@mitre.org
Secondary
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H
CVE-2026-40683: In OpenStack Keystone before 28.0.1, the LDAP identity backend does not convert the user enabled attribute to a boolean when the user_enabled_invert configuration option is False (the default). The _ldap_res_to_model method in the UserApi class only performed string-to-boolean conversion when user_enabled_invert was True. When False, the raw string value from LDAP (e.g., "FALSE") was used directly. Since non-empty strings are truthy in Python, users marked as disabled in LDAP were treated as enabled by Keystone, allowing them to authenticate and perform actions. All deployments using the LDAP identity backend without user_enabled_invert=True or user_enabled_emulation are affected.
The exploitability of CVE-2026-40683 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
This vulnerability, CVE-2026-40683, requires a high level of attack complexity and low privileges, making it difficult but not impossible to exploit. Organizations should ensure robust security configurations to mitigate risks.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2026-40683, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2026-40683, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
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