CVE-2026-45890xen-netback: reject zero-queue configuration from guest
- 5.5MediumCVSS base score
- 0.12%Exploitation in 30 daysEPSS · top 98% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By Linux
- 14 days later
· 14 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.12% · top 98% of all CVEs (14 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d – < 2993e0f904c45f8af12917344bb1cac7ccd05a60
- affected 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d – < 787bfa423228c4b02ba3368128f625d579085353
- affected 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d – < ce66d6786de45b7ed9cbbdc0988054bf09e58f54
- affected 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d – < 88b0fced1bbbfdb356a007592604008ffc93a6a1
- affected 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d – < ec4859ac5c933e3315543a61adc1ca4358006a41
- affected 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d – < 654780dee9eae419e1648ea58462c4efe54518fa
- affected 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d – < d99f69ddc70fd9f4b8148add62209a1a8eb5c615
- affected 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d – < 6d1dc8014334c7fb25719999bca84d811e60a559
- affected 3.16
- unaffected < 3.16
- unaffected 5.10.252 – ≤ 5.10.*
- unaffected 5.15.202 – ≤ 5.15.*
- unaffected 6.1.165 – ≤ 6.1.*
- unaffected 6.6.128 – ≤ 6.6.*
- unaffected 6.12.75 – ≤ 6.12.*
- unaffected 6.18.14 – ≤ 6.18.*
- unaffected 6.19.4 – ≤ 6.19.*
- unaffected 7.0 – ≤ *
References
References8
- https://git.kernel.org/stable/c/2993e0f904c45f8af12917344bb1cac7ccd05a60 (opens in a new tab)
- https://git.kernel.org/stable/c/787bfa423228c4b02ba3368128f625d579085353 (opens in a new tab)
- https://git.kernel.org/stable/c/ce66d6786de45b7ed9cbbdc0988054bf09e58f54 (opens in a new tab)
- https://git.kernel.org/stable/c/88b0fced1bbbfdb356a007592604008ffc93a6a1 (opens in a new tab)
- https://git.kernel.org/stable/c/ec4859ac5c933e3315543a61adc1ca4358006a41 (opens in a new tab)
- https://git.kernel.org/stable/c/654780dee9eae419e1648ea58462c4efe54518fa (opens in a new tab)
- https://git.kernel.org/stable/c/d99f69ddc70fd9f4b8148add62209a1a8eb5c615 (opens in a new tab)
- https://git.kernel.org/stable/c/6d1dc8014334c7fb25719999bca84d811e60a559 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-32356 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-45890)Record last updated .