Review reviewHigh

CVE-2026-40683

OpenStack Keystone

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 LD...

CVSS: 7.7
EPSS: 0.32%
CISA KEV: Not listed
Published: 2026.04.15

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.32%

Technical severityCVSS 7.7

Vulnerability overview

Affected product and versions

Product: OpenStack Keystone
Affected versions: >= 8.0.0 < 25.0.1, >= 26.0.0 < 26.1.1, >= 27.0.0 < 27.0.1, >= 28.0.0 < 28.0.1
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that OpenStack Keystone and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H
CWE: CWE-843