Vulnerability · Published Apr 14, 2026 · Assigned by mitre
CVE-2026-40683
High 7.7
In plain English
A high-severity type confusion in Keystone from OpenStack. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | keystone | 2:22.0.2-0+deb12u2 | DEBIAN-CVE-2026-40683 |
| Debian:13 | keystone | 2:27.0.0-3+deb13u3 | DEBIAN-CVE-2026-40683 |
| Debian:14 | keystone | 2:29.0.0~rc1-2 | DEBIAN-CVE-2026-40683 |
| PyPI | keystone | 28.0.1 | GHSA-pfx2-9x9m-7ghx |
| PyPI | keystone | 28.0.1 | PYSEC-2026-2550 |
| Ubuntu:22.04:LTS | keystone | 2:21.0.1-0ubuntu2.4 | UBUNTU-CVE-2026-40683 |
| Ubuntu:24.04:LTS | keystone | 2:25.0.0-0ubuntu1.4 | UBUNTU-CVE-2026-40683 |
| Ubuntu:25.10 | keystone | 2:28.0.0-0ubuntu1.3 | UBUNTU-CVE-2026-40683 |
Affected products (as reported)
Weakness: CWE-843 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H