VulnerabilityAwaiting Analysis

CVE-2026-40683

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.

HIGH 7.7EPSS 0.34%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.34%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 7.7 HIGHCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H
EPSS: 0.34% probability · 27th percentile
CISA KEV: Not listed
Weakness: CWE-843
Source: cve@mitre.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.