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CVE-2026-45890

📛 CVE Title

xen-netback: reject zero-queue configuration from guest

⬇ Download JSON ⚠ View as Threat

Description

In the Linux kernel, the following vulnerability has been resolved: xen-netback: reject zero-queue configuration from guest A malicious or buggy Xen guest can write "0" to the xenbus key "multi-queue-num-queues". The connect() function in the backend only validates the upper bound (requested_num_queues > xenvif_max_queues) but not zero, allowing requested_num_queues=0 to reach vzalloc(array_size(0, sizeof(struct xenvif_queue))), which triggers WARN_ON_ONCE(!size) in __vmalloc_node_range(). On systems with panic_on_warn=1, this allows a guest-to-host denial of service. The Xen network interface specification requires the queue count to be "greater than zero". Add a zero check to match the validation already present in xen-blkback, which has included this guard since its multi-queue support was added.

Overview

State
PUBLISHED
Assigner (CNA)
Linux
CVSS severity
high
CVSS score
CVSS 8.4 / 10 8.4 8.4 / 10
CVSS vector
AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Effective score
8.4 / 10 HIGH source: CNA overview
CWE(s)
—
Reserved
2026-05-13
Published
2026-05-27 12:17 UTC
Last updated
2026-05-27 12:17 UTC
Source
https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/45xxx/CVE-2026-45890.json
Linked Threat
CVE-2026-45890 — CVE-2026-45890

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published
2026-05-27 14:17:03 UTC
NVD last modified
2026-06-25 21:13:36 UTC
NVD CVSS v3.1
CVSS 5.5 / 10 5.5 5.5 / 10 MEDIUM source: nvd@nist.gov
NVD CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Exploitability subscore
1.8 / 10
Impact subscore
3.6 / 10
EPSS score
0.0012 (probability of exploitation in next 30 days)
EPSS percentile
2.40% vs all CVEs — higher = more likely to be exploited, as of 2026-07-26

NVD / KEV / EPSS data refreshed 2026-07-27 11:54 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID
EUVD-2026-32356
Assigner
Linux
Published
May 27, 2026, 12:17:01 PM
Updated
May 27, 2026, 12:17:01 PM
EUVD base score
0.0 / 10
EUVD-reported EPSS
0.1200
Vendors
Linux
Products
Linux (8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <ce66d6786de45b7ed9cbbdc0988054bf09e58f54)
Linux (patch: 6.6.128)
Linux (8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <ec4859ac5c933e3315543a61adc1ca4358006a41)
Linux (patch: 6.12.75)
Linux (patch: 5.15.202)
Linux (8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <d99f69ddc70fd9f4b8148add62209a1a8eb5c615)
Linux (3.16)
Linux (patch: 6.18.14)
Linux (patch: 7.0)
Linux (patch: 0)
Linux (patch: 6.19.4)
Linux (8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <2993e0f904c45f8af12917344bb1cac7ccd05a60)
Linux (patch: 6.1.165)
Linux (8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <787bfa423228c4b02ba3368128f625d579085353)
Linux (8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <6d1dc8014334c7fb25719999bca84d811e60a559)
Linux (patch: 5.10.252)
Linux (8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <654780dee9eae419e1648ea58462c4efe54518fa)
Linux (8d3d53b3e43363e79ab9a9ecc149b06c1314b25d <88b0fced1bbbfdb356a007592604008ffc93a6a1)
Aliases
GHSA-jc43-3m97-6p35

ENISA description: In the Linux kernel, the following vulnerability has been resolved: xen-netback: reject zero-queue configuration from guest A malicious or buggy Xen guest can write "0" to the xenbus key "multi-queue-num-queues". The connect() function in the backend only validates the upper bound (requested_num_queues > xenvif_max_queues) but not zero, allowing requested_num_queues=0 to reach vzalloc(array_size(0, sizeof(struct xenvif_queue))), which triggers WARN_ON_ONCE(!size) in __vmalloc_node_range(). On systems with panic_on_warn=1, this allows a guest-to-host denial of service. The Xen network interface specification requires the queue count to be "greater than zero". Add a zero check to match the validation already present in xen-blkback, which has included this guard since its multi-queue support was added.

EUVD references (8)

Affected products (2)
VendorProductVersionsPlatforms
Linux Linux 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d (affected), 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d (affected), 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d (affected), 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d (affected), 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d (affected), 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d (affected), 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d (affected), 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d (affected) —
Linux Linux 3.16 (affected), 0 (unaffected), 5.10.252 (unaffected), 5.15.202 (unaffected), 6.1.165 (unaffected), 6.6.128 (unaffected), 6.12.75 (unaffected), 6.18.14 (unaffected), 6.19.4 (unaffected), 7.0 (unaffected) —

Affected products — CPE 2.3 (1) NVD

NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.

  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Vendor references (8)

References embedded in the original CVE record by the assigning CNA.

Web references (11)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

NVD-tagged references (8)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

Remediations (19)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-45890.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/xen-netback/xenbus.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2993e0f904c45f8af12917344bb1cac7ccd05a60",
              "status": "affected",
              "version": "8d3d53b3e43363e79ab9a9ecc149b06c1314b25d",
              "versionType": "git"
            },
            {
              "lessThan": "787bfa423228c4b02ba3368128f625d579085353",
              "status": "affected",
              "version": "8d3d53b3e43363e79ab9a9ecc149b06c1314b25d",
              "versionType": "git"
            },
            {
              "lessThan": "ce66d6786de45b7ed9cbbdc0988054bf09e58f54",
              "status": "affected",
              "version": "8d3d53b3e43363e79ab9a9ecc149b06c1314b25d",
              "versionType": "git"
            },
            {
              "lessThan": "88b0fced1bbbfdb356a007592604008ffc93a6a1",
              "status": "affected",
              "version": "8d3d53b3e43363e79ab9a9ecc149b06c1314b25d",
              "versionType": "git"
            },
            {
              "lessThan": "ec4859ac5c933e3315543a61adc1ca4358006a41",
              "status": "affected",
              "version": "8d3d53b3e43363e79ab9a9ecc149b06c1314b25d",
              "versionType": "git"
            },
            {
              "lessThan": "654780dee9eae419e1648ea58462c4efe54518fa",
              "status": "affected",
              "version": "8d3d53b3e43363e79ab9a9ecc149b06c1314b25d",
              "versionType": "git"
            },
            {
              "lessThan": "d99f69ddc70fd9f4b8148add62209a1a8eb5c615",
              "status": "affected",
              "version": "8d3d53b3e43363e79ab9a9ecc149b06c1314b25d",
              "versionType": "git"
            },
            {
              "lessThan": "6d1dc8014334c7fb25719999bca84d811e60a559",
              "status": "affected",
              "version": "8d3d53b3e43363e79ab9a9ecc149b06c1314b25d",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/xen-netback/xenbus.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.16"
            },
            {
              "lessThan": "3.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.252",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.202",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.165",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.128",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.75",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.252",
                  "versionStartIncluding": "3.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.202",
                  "versionStartIncluding": "3.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.165",
                  "versionStartIncluding": "3.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.128",
                  "versionStartIncluding": "3.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.75",
                  "versionStartIncluding": "3.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.14",
                  "versionStartIncluding": "3.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.4",
                  "versionStartIncluding": "3.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "3.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxen-netback: reject zero-queue configuration from guest\n\nA malicious or buggy Xen guest can write \"0\" to the xenbus key\n\"multi-queue-num-queues\". The connect() function in the backend only\nvalidates the upper bound (requested_num_queues > xenvif_max_queues)\nbut not zero, allowing requested_num_queues=0 to reach\nvzalloc(array_size(0, sizeof(struct xenvif_queue))), which triggers\nWARN_ON_ONCE(!size) in __vmalloc_node_range().\n\nOn systems with panic_on_warn=1, this allows a guest-to-host denial\nof service.\n\nThe Xen network interface specification requires\nthe queue count to be \"greater than zero\".\n\nAdd a zero check to match the validation already present\nin xen-blkback, which has included this\nguard since its multi-queue support was added."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-27T12:17:01.466Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/2993e0f904c45f8af12917344bb1cac7ccd05a60"
        },
        {
          "url": "https://git.kernel.org/stable/c/787bfa423228c4b02ba3368128f625d579085353"
        },
        {
          "url": "https://git.kernel.org/stable/c/ce66d6786de45b7ed9cbbdc0988054bf09e58f54"
        },
        {
          "url": "https://git.kernel.org/stable/c/88b0fced1bbbfdb356a007592604008ffc93a6a1"
        },
        {
          "url": "https://git.kernel.org/stable/c/ec4859ac5c933e3315543a61adc1ca4358006a41"
        },
        {
          "url": "https://git.kernel.org/stable/c/654780dee9eae419e1648ea58462c4efe54518fa"
        },
        {
          "url": "https://git.kernel.org/stable/c/d99f69ddc70fd9f4b8148add62209a1a8eb5c615"
        },
        {
          "url": "https://git.kernel.org/stable/c/6d1dc8014334c7fb25719999bca84d811e60a559"
        }
      ],
      "title": "xen-netback: reject zero-queue configuration from guest",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-45890",
    "datePublished": "2026-05-27T12:17:01.466Z",
    "dateReserved": "2026-05-13T15:03:33.083Z",
    "dateUpdated": "2026-05-27T12:17:01.466Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}