CVE-2026-40683Network attack vector

Authentication bypass via truthy LDAP enabled strings

Published Apr 14, 2026 · Updated Apr 14, 2026

Authentication bypass in OpenStack Keystone before 28.0.1 allows remote authenticated users disabled in LDAP to access OpenStack APIs. UserApi._ldap_res_to_model leaves the enabled attribute as a raw string when user_enabled_invert is false, so Python treats values such as "FALSE" as true. LDAP-backed deployments without enabled inversion or emulation accept valid credentials for directory-disabled accounts, restoring the account's assigned access.

CVSS severity7.7
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in OpenStack Keystone before 28.0.1 allows remote authenticated users disabled in LDAP to access OpenStack APIs. UserApi._ldap_res_to_model leaves the enabled attribute as a raw string when user_enabled_invert is false, so Python treats values such as "FALSE" as true. LDAP-backed deployments without enabled inversion or emulation accept valid credentials for directory-disabled accounts, restoring the account's assigned access.

The record

CVE
CVE-2026-40683
Published
Apr 14, 2026
Updated
Apr 14, 2026
Vendor
OpenStack
Product
Keystone
Classifications
CWE-843, T1078
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=26.0.0 <26.1.1
  2. Affected versionversion=27.0.0 <27.0.1
  3. Affected versionversion=28.0.0 <28.0.1
  4. Affected versionversion=8.0.0 <25.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenStack · Keystoneversion=26.0.0 <26.1.1; version=27.0.0 <27.0.1; version=28.0.0 <28.0.1; version=8.0.0 <25.0.1

Published CVSS scores

7.7GitHubCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-843Access of Resource Using Incompatible Type ('Type Confusion')
T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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