CVE-2026-45890

Guest-to-host denial of service via zero-queue configuration

Published May 27, 2026 · Updated May 27, 2026

Denial of service in Linux Kernel xen-netback allows guest OS users to crash a Xen host via a zero-queue backend request. The connect() function accepts multi-queue-num-queues=0, passes a zero-sized allocation to vzalloc(), and triggers WARN_ON_ONCE in __vmalloc_node_range(). The host crashes only when panic_on_warn=1; otherwise the request produces a kernel warning, with no reported confidentiality or integrity impact.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Linux Kernel xen-netback allows guest OS users to crash a Xen host via a zero-queue backend request. The connect() function accepts multi-queue-num-queues=0, passes a zero-sized allocation to vzalloc(), and triggers WARN_ON_ONCE in __vmalloc_node_range(). The host crashes only when panic_on_warn=1; otherwise the request produces a kernel warning, with no reported confidentiality or integrity impact.

The record

CVE
CVE-2026-45890
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=3.16
  2. Affected versionversion=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <2993e0f904c45f8af12917344bb1cac7ccd05a60
  3. Affected versionversion=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <654780dee9eae419e1648ea58462c4efe54518fa
  4. Affected versionversion=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <6d1dc8014334c7fb25719999bca84d811e60a559
  5. Affected versionversion=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <787bfa423228c4b02ba3368128f625d579085353
  6. Affected versionversion=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <88b0fced1bbbfdb356a007592604008ffc93a6a1
  7. Affected versionversion=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <ce66d6786de45b7ed9cbbdc0988054bf09e58f54
  8. Affected versionversion=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <d99f69ddc70fd9f4b8148add62209a1a8eb5c615
  9. Affected versionversion=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <ec4859ac5c933e3315543a61adc1ca4358006a41

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.16; version=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <2993e0f904c45f8af12917344bb1cac7ccd05a60; version=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <654780dee9eae419e1648ea58462c4efe54518fa; version=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <6d1dc8014334c7fb25719999bca84d811e60a559; version=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <787bfa423228c4b02ba3368128f625d579085353; version=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <88b0fced1bbbfdb356a007592604008ffc93a6a1; version=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <ce66d6786de45b7ed9cbbdc0988054bf09e58f54; version=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <d99f69ddc70fd9f4b8148add62209a1a8eb5c615; version=8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <ec4859ac5c933e3315543a61adc1ca4358006a41

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

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No observations available

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

Weakness, pattern, technique

T1499.004Application or System Exploitation

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

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Your stack

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