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NVD / CVE Program· CNA Linux

CVE-2026-45890: xen-netback: reject zero-queue configuration from guest

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.12% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 2993e0f904c45f8af12917344bb1cac7ccd05a60, 654780dee9eae419e1648ea58462c4efe54518fa, 6d1dc8014334c7fb25719999bca84d811e60a559.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 2993e0f904c45f8af12917344bb1cac7ccd05a60, 654780dee9eae419e1648ea58462c4efe54518fa, 6d1dc8014334c7fb25719999bca84d811e60a559 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 27, 2026
Updated
Jun 25, 2026
EPSS
0.1% · 2th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel3.16 and later · before 5.10.252
  • linux linux kernel5.11 and later · before 5.15.202
  • linux linux kernel5.16 and later · before 6.1.165
  • linux linux kernel6.2 and later · before 6.6.128
  • linux linux kernel6.7 and later · before 6.12.75
  • linux linux kernel6.13 and later · before 6.18.14
  • linux linux kernel6.19 and later · before 6.19.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 3.16affected
    • 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d and later · before 2993e0f904c45f8af12917344bb1cac7ccd05a60affected · git
    • 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d and later · before 787bfa423228c4b02ba3368128f625d579085353affected · git
    • 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d and later · before ce66d6786de45b7ed9cbbdc0988054bf09e58f54affected · git
    • 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d and later · before 88b0fced1bbbfdb356a007592604008ffc93a6a1affected · git
    • 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d and later · before ec4859ac5c933e3315543a61adc1ca4358006a41affected · git
    • 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d and later · before 654780dee9eae419e1648ea58462c4efe54518faaffected · git
    • 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d and later · before d99f69ddc70fd9f4b8148add62209a1a8eb5c615affected · git
    • 8d3d53b3e43363e79ab9a9ecc149b06c1314b25d and later · before 6d1dc8014334c7fb25719999bca84d811e60a559affected · git
    • before 3.16not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.170-16.1.170-1
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.18.14-16.18.14-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-45888May 27, 2026 · md/raid1: fix memory leak in raid1_run()
    22Monitor
  • ← EarlierCVE-2026-45889May 27, 2026 · mptcp: do not account for OoO in mptcp_rcvbuf_grow()
    22Monitor
  • Later →CVE-2026-45891May 27, 2026 · net: hns3: fix double free issue for tx spare buffer
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux2993e0f904c45f8af12917344bb1cac7ccd05a60Vendor (CNA)
Linux Linux654780dee9eae419e1648ea58462c4efe54518faVendor (CNA)
Linux Linux6d1dc8014334c7fb25719999bca84d811e60a559Vendor (CNA)
Linux Linux787bfa423228c4b02ba3368128f625d579085353Vendor (CNA)
Linux Linux88b0fced1bbbfdb356a007592604008ffc93a6a1Vendor (CNA)
Linux Linuxce66d6786de45b7ed9cbbdc0988054bf09e58f54Vendor (CNA)
Linux Linuxd99f69ddc70fd9f4b8148add62209a1a8eb5c615Vendor (CNA)
Linux Linuxec4859ac5c933e3315543a61adc1ca4358006a41Vendor (CNA)
debian:linux6.1.170-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records