Is CVE-2026-40683 actively exploited?

No active exploitation of CVE-2026-40683 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-40683 be exploited remotely?

Yes. CVE-2026-40683 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-40683?

CVE-2026-40683 has a CVSS score of 7.7 (HIGH).

HOME VULNERABILITIESCVE-2026-40683

HIGH

CVE-2026-40683

CWE-843Published: April 14, 2026· Updated: Apr 17, 2026

7.7

CVSS v3.1

EPSS:0.01%probability of exploitation in 30 daysPercentile:3.2th

Official Description

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.

NVD Source

Technical Analysis

CVE-2026-40683 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.7.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.