Staging Environment: Content and features may be unstable or change without notice.
Advisory details: pypa / keystone/PYSEC-2026-600
Advisory ID pypa/keystone/PYSEC-2026-600
Aliases CVE-2026-42999
GHSA-2r23-2g6v-2m5f
PYSEC-2026-600
Summary 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).
Status Published
Exploitability 0.5
Weighted Severity 7.9
Risk 4.0
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (0)
There are no known CWE.
System Score Found at
cvssv3.1 8.8 https://github.com/pypa/advisory-database/blob/main/vulns/keystone/PYSEC-2026-600.yaml
Reference id Reference type URL
https://bugzilla.redhat.com/show_bug.cgi?id=2482840
https://security.openstack.org/ossa/OSSA-2026-015.html
2148398 Other https://bugs.launchpad.net/keystone/+bug/2148398
CVE-2026-42999 https://access.redhat.com/security/cve/CVE-2026-42999
CVE-2026-42999.JSON https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42999.json
GHSA-2r23-2g6v-2m5f https://github.com/advisories/GHSA-2r23-2g6v-2m5f

No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/pypa/advisory-database/blob/main/vulns/keystone/PYSEC-2026-600.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2026-05-28T19:42:13Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/42xxx/CVE-2026-42999.json

Source Advisory: vulnrichment/CVE-2026-42999

View SSVC decision tree 
[{'Exploitation': 'none'},
 {'Automatable': 'no'},
 {'Technical Impact': 'partial'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]

Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2026-05-28T19:42:13Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/42xxx/CVE-2026-42999.json

Source Advisory: vulnrichment/CVE-2026-42999

View SSVC decision tree 
[{'Exploitation': 'none'},
 {'Automatable': 'no'},
 {'Technical Impact': 'partial'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]