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Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : OpenStack Keystone vulnerabilities (USN-8433-1)

high Nessus Plugin ID 321365

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Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8433-1 advisory.

 It was discovered that OpenStack Keystone allowed restricted application credentials to create EC2 credentials. An authenticated attacker with only a reader role could possibly use this issue to bypass the role restrictions imposed on the application credential. (CVE-2026-33551)

 It was discovered that the OpenStack Keystone LDAP identity backend did not correctly convert the user enabled attribute to a boolean value. An attacker could possibly use this issue to authenticate as a user disabled in LDAP. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 25.10.
 (CVE-2026-40683)

 It was discovered that OpenStack Keystone's application credential authentication plugin did not verify that the user supplied in an authentication request matched the credential owner. An authenticated attacker could possibly impersonate another user and gain access to their tokens and credentials.
 (CVE-2026-42998)

 It was discovered that OpenStack Keystone's RBAC policy enforcer unconditionally merged the raw JSON request body into the policy enforcement dictionary, overwriting trusted target data. An authenticated attacker could possibly use this issue to inject arbitrary policy attributes to bypass RBAC checks.
 (CVE-2026-42999)

 It was discovered that OpenStack Keystone allowed an attacker with the member role to escalate privileges to admin by chaining application credential impersonation with Keystone trusts. An attacker could possibly use this issue to create a persistent trust delegating the victim's admin role to themselves.
 (CVE-2026-43000)

 It was discovered that OpenStack Keystone did not validate that the project_id for an EC2 credential matched the project of the authenticating application credential. An attacker with valid credentials for one project could possibly use this issue to create EC2 credentials targeting a different project.
 (CVE-2026-43001)

 It was discovered that OpenStack Keystone's federated token rescoping mechanism did not propagate the original token's expiry to the newly issued token. A remote attacker could possibly use this issue to maintain access indefinitely by repeatedly rescoping tokens before expiry. (CVE-2026-44394)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected keystone, keystone-common and / or python3-keystone packages.

See Also

https://ubuntu.com/security/notices/USN-8433-1

Plugin Details

Severity: High

ID: 321365

File Name: ubuntu_USN-8433-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 6/17/2026

Updated: 6/17/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.7

Percentile: 96.44

CVSS v2

Risk Factor: High

Base Score: 9

Temporal Score: 7

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2026-43000

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:25.10, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:keystone, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:python3-keystone, cpe:/o:canonical:ubuntu_linux:26.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:keystone-common

Required KB Items: Host/cpu, Host/Debian/dpkg-l, Host/Ubuntu, Host/Ubuntu/release

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 6/16/2026

Vulnerability Publication Date: 4/10/2026

Reference Information

CVE: CVE-2026-33551, CVE-2026-40683, CVE-2026-42998, CVE-2026-42999, CVE-2026-43000, CVE-2026-43001, CVE-2026-44394

USN: 8433-1