CVE-2026-43000

Aliases:GHSA-q623-f4j4-p4xjPYSEC-2026-601
Advisory lineage Upstream: 0 Downstream: 3
Analyzed
Published: 28 May 2026, 00:00
Last modified:15 Jul 2026, 00:56

Vulnerability Summary

Overall Risk (default)
medium
45/100
CVSS Score
8.8 HIGH
v3.1 (nvd)
EPSS Score
0.33% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
1 found
Dark Web
Not detected

Timeline

28 May 2026, 00:00
Published
Vulnerability first disclosed
15 Jul 2026, 00:56
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v3.1•MEDIUM•Score: 6CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L
  • v3.1•HIGH•Score: 8.8CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.33%• Percentile: 25%

Techniques & Countermeasures

  • 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.

  • CWE-266•Incorrect Privilege Assignment

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

Affected Systems

  • openstack•keystone

    ≥ 14.0.0, < 27.0.2 | ≥ 28.0.0, < 28.0.2 | ≥ 29.0.0, < 29.0.2

  • PyPI•keystone

    ≥ 14.0.0, < 27.0.2 | ≥ 28.0.0, < 28.0.2 | ≥ 29.0.0, < 29.0.2

References (9)