OpenStack Nova DoS by rebuilding the same instance with a new image multiple times

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.6 · CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS

• CVE-2017-17051: 1.99% estimated exploitation activity in the next 30 days; percentile 80.66 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

An issue was discovered in the default FilterScheduler in OpenStack Nova 16.0.3. By repeatedly rebuilding an instance with new images, an authenticated user may consume untracked resources on a hypervisor host leading to a denial of service, aka doubled resource allocations. This regression was introduced with the fix for OSSA-2017-005 (CVE-2017-16239); however, only Nova stable/pike or later deployments with that fix applied and relying on the default FilterScheduler are affected.

Published by the source

13 May 2022, 01:44 UTC

Last modified by the source

6 Jul 2026, 08:11 UTC

Source last checked

26 Oct 2026, 13:13 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-vq76-rxx3-4r4r

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-vq76-rxx3-4r4r

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# Patch Next advisory brief: CVE-2017-17051

Advisory: OpenStack Nova DoS by rebuilding the same instance with a new image multiple times
IDs: CVE-2017-17051, GHSA-vq76-rxx3-4r4r
Record: https://patchnext.com/advisories/cve-2017-17051 (revision 2, source checked 26 Oct 2026, 13:13 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: nova 16.0.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI nova: affected < 16.0.4; fixed in 16.0.4

## Suggested inspection (read-only)
- `python -m pip show nova`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on nova.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-vq76-rxx3-4r4r (OSV record GHSA-vq76-rxx3-4r4r lists affected ranges: PyPI nova >=0 <16.0.4 (fixed))
- Verified: https://github.com/advisories/GHSA-vq76-rxx3-4r4r (GitHub-reviewed advisory GHSA-vq76-rxx3-4r4r lists affected ranges: PyPI nova >=0 <16.0.4)

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