NVD / CVE Program· CNA Linux

CVE-2026-64562: KVM: nVMX: Hide shadow VMCS right after VMCLEAR

Noroxi assessment

Priority: Monitor (action score 35/100)

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: 0.16% (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 1dabef6e206568bf9d9ade74f6e56a48ea35695d, 4f50e6aec16f69627dbad5704d1e90a255d766a7, 589419470030a89f16cf19300658b6dc644ca946; azl3 kernel 6.6.145.2-1 on Azure Linux 3.0 6.6.150.1-1.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 1dabef6e206568bf9d9ade74f6e56a48ea35695d, 4f50e6aec16f69627dbad5704d1e90a255d766a7, 589419470030a89f16cf19300658b6dc644ca946; azl3 kernel 6.6.145.2-1 on Azure Linux 3.0 6.6.150.1-1 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: KVM: nVMX: Hide shadow VMCS right after VMCLEAR free_nested() frees the shadow VMCS while vmcs01 still points to it. But because it is asynchronous with respect to loaded_vmcs_clear(), the vCPU might migrate before the pointer is cleared and __loaded_vmcs_clear() may then execute VMCLEAR. The VMCS needs to stay attached until its explicit VMCLEAR completes, but then it can be hidden and the page safely freed.

HighCVSS 8.8 · v3.1—No exploit Fix available

Memory safety

Published: Aug 4, 2026
Updated: Nov 3, 2026
EPSS: 0.1% · 5th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 35 / 40 · 8.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Linux: 8.8; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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

If any of these changes, we'll tell you in the daily email digest.

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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
- 4.9affected
- 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 and later · before b82c3144d8264265448292ca406f60bafeba3b6faffected · git
- 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 and later · before 4f50e6aec16f69627dbad5704d1e90a255d766a7affected · git
- 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 and later · before dc3eecfa219ebc9d01eaf7d1abd1441efe884dabaffected · git
- 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 and later · before af56298e9d86e6098cd1d2e155cb2949b7c45412affected · git
- 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 and later · before 589419470030a89f16cf19300658b6dc644ca946affected · git
- 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 and later · before 8001d2ce9d9bd09118ce523aef595aa094573ae3affected · git
- 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 and later · before 1dabef6e206568bf9d9ade74f6e56a48ea35695daffected · git
- 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 and later · before 622ebfac01ba4f9c0060cebd41257fe46fc4a0b3affected · git
- before 4.9not affected · semver

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.187-1	6.1.187-1
Debian:12	linux-6.12	before 6.12.101-1~deb12u1	6.12.101-1~deb12u1
Debian:13	linux	before 6.12.101-1	6.12.101-1
Debian:14	linux	before 7.1.6-1	7.1.6-1

Same product

linux: all records

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-2022-4994Jul 30, 2026 · KVM: x86: wean fast IN from emulator_pio_in
0Monitor
← EarlierCVE-2026-64561Aug 4, 2026 · KVM: x86: Check for invalid/obsolete root *after* making MMU pages available
35Monitor
Later →CVE-2026-64563Aug 4, 2026 · rhashtable: clear stale iter->p on table restart
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 / package	Fixed version	Source
Linux Linux	1dabef6e206568bf9d9ade74f6e56a48ea35695d	Vendor (CNA)
Linux Linux	4f50e6aec16f69627dbad5704d1e90a255d766a7	Vendor (CNA)
Linux Linux	589419470030a89f16cf19300658b6dc644ca946	Vendor (CNA)
Linux Linux	622ebfac01ba4f9c0060cebd41257fe46fc4a0b3	Vendor (CNA)
Linux Linux	8001d2ce9d9bd09118ce523aef595aa094573ae3	Vendor (CNA)
Linux Linux	af56298e9d86e6098cd1d2e155cb2949b7c45412	Vendor (CNA)
Linux Linux	b82c3144d8264265448292ca406f60bafeba3b6f	Vendor (CNA)
Linux Linux	dc3eecfa219ebc9d01eaf7d1abd1441efe884dab	Vendor (CNA)
azl3 kernel 6.6.145.2-1 on Azure Linux 3.0	6.6.150.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.187-1 · Debian:12	Package registry (OSV)
debian:linux-6.12	6.12.101-1~deb12u1 · Debian:12	Package 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.

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.

CVE-2026-645640 days apartsctp: don't free the ASCONF's own transport in DEL-IP processing
39Monitor
CVE-2026-681276 days apartila: reload IPv6 header after pskb_may_pull in checksum adjust
39Monitor
CVE-2026-681446 days apartphonet: pep: fix use-after-free in pep_get_sb()
39Monitor
CVE-2026-681566 days apartlibceph: refresh auth->authorizer_buf{,_len} after authorizer update
39Monitor
CVE-2026-683816 days apartksmbd: pin conn during async oplock break notification
39Monitor
CVE-2026-684266 days apartxfrm: fix stale skb->prev after async crypto steals a GSO segment
39Monitor

Chain candidates

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

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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.

TR-26-0742 · Aug 5, 2026(Linux Kernel Güvenlik Bildirimi)

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: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Changed
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

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

SSVC exploitation— → noneOct 16, 2026, 5:07 PM UTC
Fix✗ → ✓Sep 28, 2026, 10:07 PM UTC

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

References

git.kernel.org/stable/c/1dabef6e206568bf9d9ade74f6e56a48ea35695d

Show all references (7 more)

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

All records