CVE-2026-40683 — HIGH (7.7)

Vulnerability 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 Score

7.7

HIGH

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality

LOW

Integrity

LOW

Availability

HIGH

Related Weaknesses (CWE)

CWE-843

References

FAQ

What is CVE-2026-40683?

CVE-2026-40683 is a vulnerability with a CVSS score of 7.7 (HIGH). 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 _l...

How severe is CVE-2026-40683?

CVE-2026-40683 has been rated HIGH with a CVSS base score of 7.7/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-40683?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.