CVE-2026-46448Network attack vector

Authenticated constraint bypass via internal scheduler hints

Published Jun 16, 2026 · Updated Jun 16, 2026

Scheduler-hint injection in affected OpenStack Nova releases allows remote authenticated users to bypass Placement resource claims. The server create API accepts internal _nova-prefixed scheduler hints from client requests instead of stripping them before candidate selection and request pre-filters. A tenant account is required; crafted hints can create instances without Placement allocations, exhaust compute resources, evade host constraints, and leave cross-tenant data on NVMe devices after deletion.

CVSS severity5.4
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Scheduler-hint injection in affected OpenStack Nova releases allows remote authenticated users to bypass Placement resource claims. The server create API accepts internal _nova-prefixed scheduler hints from client requests instead of stripping them before candidate selection and request pre-filters. A tenant account is required; crafted hints can create instances without Placement allocations, exhaust compute resources, evade host constraints, and leave cross-tenant data on NVMe devices after deletion.

The record

CVE
CVE-2026-46448
Published
Jun 16, 2026
Updated
Jun 16, 2026
Vendor
OpenStack
Product
Nova
Classifications
CWE-669, T1496
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=18.0.0 <31.3.1
  2. Affected versionversion=32.0.0 <32.2.1
  3. Affected versionversion=33.0.0 <33.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenStack · Novaversion=18.0.0 <31.3.1; version=32.0.0 <32.2.1; version=33.0.0 <33.0.2

Published CVSS scores

8.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H
5.4MITRECVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-669Incorrect Resource Transfer Between Spheres
T1496Resource Hijacking

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo