CVE-2026-40683

HIGH
7.7
CVSS Score
Published: April 14, 2026 at 08:05 PM UTC
Updated: August 5, 2026 at 07:34 PM UTC
1 product affected across 1 vendorKeystone

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Severity
HIGH7.7
Exploit prediction
EPSS 0.3%
SSVC
No known 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

26.0.0 ≤ v < 26.1.127.0.0 ≤ v < 27.0.128.0.0 ≤ v < 28.0.18.0.0 ≤ v < 25.0.126.0.027.0.028.0.08.0.0
Affected range stops below 25.0.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 26.1.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 27.0.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 28.0.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.7HIGHmitre
Attack Vector
NETWORK
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
HIGH
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-843

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