GHSA-JC43-3M97-6P35
Vulnerability from github – Published: 2026-05-27 15:33 – Updated: 2026-06-25 21:31In 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.
{
"affected": [],
"aliases": [
"CVE-2026-45890"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-27T14:17:03Z",
"severity": "MODERATE"
},
"details": "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 \u003e 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.",
"id": "GHSA-jc43-3m97-6p35",
"modified": "2026-06-25T21:31:20Z",
"published": "2026-05-27T15:33:15Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45890"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2993e0f904c45f8af12917344bb1cac7ccd05a60"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/654780dee9eae419e1648ea58462c4efe54518fa"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6d1dc8014334c7fb25719999bca84d811e60a559"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/787bfa423228c4b02ba3368128f625d579085353"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/88b0fced1bbbfdb356a007592604008ffc93a6a1"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ce66d6786de45b7ed9cbbdc0988054bf09e58f54"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d99f69ddc70fd9f4b8148add62209a1a8eb5c615"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ec4859ac5c933e3315543a61adc1ca4358006a41"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.