GHSA-q623-f4j4-p4xj CVE-2026-43000 PYSEC-2026-601

OpenStack Keystone has an Incorrect Authorization issue

High PyPI

Severity: 6.0 / 10; High · CVSS 3.1
Exploit chance (EPSS): 0.33%; Chance of exploitation in the next 30 days. Higher than 25.88% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-266 Incorrect Privilege Assignment; CWE-863 Incorrect Authorization
Fix: 27.0.2; Upgrade keystone to this version or later

Description

An issue was discovered in OpenStack Keystone before 29.0.2. When combined with an application credential impersonation vulnerability, an attacker with the member role on a project can escalate to admin by chaining unrestricted application credentials with Keystone trusts. The impersonated token carries the victim's identity, which passes the trustor validation check. Keystone then validates the delegated roles against the victim's actual role assignments in the database, not the roles on the requesting token. This allows the attacker to create a trust delegating the victim's admin role to themselves. The trust persists independently, and additional trusts and application credentials can be created to maintain access. All actions are logged under the victim's identity.

Affected versions

PyPI

Package	Vulnerable	Fixed in
keystone	`>= 14.0.0, < 27.0.2`	`27.0.2`
keystone	`>= 28.0.0, < 28.0.2`	`28.0.2`
keystone	`>= 29.0.0, < 29.0.2`	`29.0.2`
keystone	`>= 14.0.0, < 27.0.2` `>= 28.0.0, < 28.0.2` `>= 29.0.0, < 29.0.2`	`27.0.2` `28.0.2` `29.0.2`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

keystone PyPI → `27.0.2`

pip

pip install --upgrade "keystone>=27.0.2"

poetry

poetry add "keystone>=27.0.2"

uv

uv add "keystone>=27.0.2"

Severity breakdown

CVSS 3.1 6.0

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

Attack vector: Network
Attack complexity: High
Privileges required: Low
User interaction: None
Scope: Changed
Confidentiality: Low
Integrity: Low
Availability: Low

Weakness

CWE-266: Incorrect Privilege Assignment

A product incorrectly assigns a privilege to a particular actor, creating an unintended sphere of control for that actor.

How to prevent it

Architecture and Design, Operation: Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
Architecture and Design, Operation: Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.

CWE-863: Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

How to prevent it

Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.

References

Advisories

Packages

github.com/openstack/keystone

Timeline

May 28, 2026 Published
Oct 26, 2026 Last updated by the source
Oct 31, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-whqr-fgm5-x77q OpenStack Keystone's federated token rescoping mechanism doesn't propagate the original token's expiry to the newly issued token	High	Also affects keystone
GHSA-2r23-2g6v-2m5f OpenStack Keystone has an Authorization Bypass	High	Also affects keystone
GHSA-8f8m-wrvr-wcvf OpenStack Keystone doesn't verify that the user supplied in the authentication request matches the owner of the application credential	High	Also affects keystone
GHSA-hhq2-3832-xxcv OpenStack Keystone has an Incorrect Authorization Issue	High	Also affects keystone
GHSA-pfx2-9x9m-7ghx OpenStack Keystone: LDAP identity backend does not convert enabled attribute to boolean	High	Also affects keystone
GHSA-4phw-6824-6cfp OpenStack Keystone: Restricted application credentials can create EC2 credentials	Medium	Also affects keystone
GHSA-hcqg-5g63-7j9h OpenStack Keystone allows /v3/ec2tokens or /v3/s3tokens request with valid AWS Signature to provide Keystone authorization.	High	Also affects keystone
GHSA-cc99-whm5-mmq3 Openstack Keystone Incorrect Authorization vulnerability	Critical	Also affects keystone

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