CVE-2026-115642
Description
A flaw was found in OpenStack keystonemiddleware and Keystone. The code incorrectly treats the presence of the X-Service-Token HTTP header as sufficient to skip enforcement of application credential access rules (and can skip related token-binding checks). An attacker who holds an application credential with access_rules can bypass those restrictions by sending any non-empty X-Service-Token value; a valid service token is not required for this bypass when delay_auth_decision is enabled (typical). This allows API calls beyond what the credential was designed to permit within the attacker's existing roles. Only installing fixed keystonemiddleware and Keystone packages remediates the issue.
Statement
Red Hat OpenStack Platform and Red Hat OpenShift ship python-keystonemiddleware and openstack-keystone in multiple streams. The same access_rules bypass (header presence of X-Service-Token rather than validated service token) exists in keystonemiddleware auth_token middleware and in Keystone's own API code path; both require fixes. Any project member who can create an application credential with access_rules can bypass those rules by sending any non-empty X-Service-Token value on API requests when the service uses delay_auth_decision (common). There is no supported configuration-only workaround; apply upstream patches for keystonemiddleware and Keystone. Keystone may disclose separately from the 2026-10-29 keystonemiddleware coordinated release.
Mitigation
No mitigation is currently available that meets Red Hat Product Security standards for a complete fix.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.3 | N/A | 8.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | High |
| Integrity Impact | Low | N/A | High |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L
Red Hat CVSS v3 Score Explanation
Independent verification score for auth bypass / privilege escalation via access_rules bypass.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Files or Directories
An attacker could bypass intended access restrictions to read sensitive data, either by reading the data directly from a data store that is not correctly restricted, or by accessing insufficiently-protected, privileged functionality to read the data.
Integrity
Technical Impact: Modify Application Data; Modify Files or Directories
An attacker could bypass intended access restrictions to modify sensitive data, either by writing the data directly to a data store that is not correctly restricted, or by accessing insufficiently-protected, privileged functionality to write the data.
Access Control
Technical Impact: Gain Privileges or Assume Identity; Bypass Protection Mechanism
An attacker could bypass intended access restrictions to gain privileges by modifying or reading critical data directly, or by accessing privileged functionality.
Confidentiality,Integrity,Availability
Technical Impact: Execute Unauthorized Code or Commands
An attacker could use elevated privileges to execute unauthorized commands or code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
An attacker could gain unauthorized access to resources on the system and excessively consume those resources, leading to a denial of service.
Acknowledgements
Upstream acknowledges Nassim Abbaoui (OVHcloud) as the original reporter.
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