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NVD / CVE Program· CNA Linux

CVE-2026-97994: vhost/vdpa: reject VRING_NUM larger than device max

Noroxi assessment

Priority: Monitor (action score 0/100)

  • 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: 0.20% (FIRST EPSS).
  • Fixed version: Linux Linux 1d09201d81b7d3e276860cc7b7dbf6c6cbe8e9b4, 4875c65ca53797a0a402fe2bb54d1b12f28b3cda, 59522639a7d71cff4e20d594d0b9ea30dd0c77e0; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 1d09201d81b7d3e276860cc7b7dbf6c6cbe8e9b4, 4875c65ca53797a0a402fe2bb54d1b12f28b3cda, 59522639a7d71cff4e20d594d0b9ea30dd0c77e0; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1 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: vhost/vdpa: reject VRING_NUM larger than device max vhost_vring_set_num() accepts any non-zero power-of-two queue size that fits in 16 bits. vhost-vdpa then passes that value to set_vq_num() without comparing it with get_vq_num_max(). A process with access to /dev/vhost-vdpa-* can therefore configure a queue larger than the device advertises. With vdpa_sim, the worker can walk descriptors beyond the mapped descriptor ring. KASAN reports a 16-byte out-of-bounds read, corresponding to one vring_desc, in the vringh IOTLB path: BUG: KASAN: out-of-bounds in _copy_from_iter Read of size 16 copy_from_iotlb copydesc_iotlb vringh_getdesc_iotlb vdpasim_net_work Cache get_vq_num_max() immediately after reset. Some backends derive it from writable queue-size state, so querying it after SET_NUM may return the current size instead of the device capability. Invalidate the cached value before reset so a failed reset leaves SET_NUM disabled. For VHOST_SET_VRING_NUM, copy the complete vring state once and use the same index and size for validation, vq->num, and set_vq_num(). This ensures that validation and use operate on the same copied values.

—No exploit Fix available
Published
Sep 25, 2026
Updated
Oct 19, 2026
EPSS
0.2% · 10th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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  • 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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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.

—

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

    • 5.7affected
    • 4c8cf31885f69e86be0b5b9e6677a26797365e1d and later · before 4875c65ca53797a0a402fe2bb54d1b12f28b3cdaaffected · git
    • 4c8cf31885f69e86be0b5b9e6677a26797365e1d and later · before 1d09201d81b7d3e276860cc7b7dbf6c6cbe8e9b4affected · git
    • 4c8cf31885f69e86be0b5b9e6677a26797365e1d and later · before 68232102f20fc961327fb9e0f605a7eaadf030a9affected · git
    • 4c8cf31885f69e86be0b5b9e6677a26797365e1d and later · before 59522639a7d71cff4e20d594d0b9ea30dd0c77e0affected · git
    • 4c8cf31885f69e86be0b5b9e6677a26797365e1d and later · before ccb1dc7c527f8c925925cf92afc76ae590dac311affected · git
    • before 5.7not affected · semver
    • 6.6.158 and later · up to and including 6.6.*not affected · semver
    • 6.12.111 and later · up to and including 6.12.*not affected · semver
    • 6.18.53 and later · up to and including 6.18.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.7-17.2.7-1

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-97992Sep 25, 2026 · vhost-vdpa: protect config_ctx from being freed under the config callback
    0Monitor
  • ← EarlierCVE-2026-97993Sep 25, 2026 · vhost-vdpa: don't install the eventfd_ctx_fdget() error in config_ctx
    0Monitor
  • Later →CVE-2026-97995Sep 25, 2026 · virtio_console: do not free control-out buffers on remove
    0Monitor

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 Linux1d09201d81b7d3e276860cc7b7dbf6c6cbe8e9b4Vendor (CNA)
Linux Linux4875c65ca53797a0a402fe2bb54d1b12f28b3cdaVendor (CNA)
Linux Linux59522639a7d71cff4e20d594d0b9ea30dd0c77e0Vendor (CNA)
Linux Linux68232102f20fc961327fb9e0f605a7eaadf030a9Vendor (CNA)
Linux Linuxccb1dc7c527f8c925925cf92afc76ae590dac311Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.06.6.158.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · 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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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.

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

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

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✗ → ✓

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References

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