Skip to content
Noroxi
CVE-2026-89775· NVD / CVE Program· CNA Linux

KVM: arm64: Handle negative S1 walk levels in VNCR TLB size evaluation

Noroxi assessment

Priority: Monitor (action score 37/100)

  • 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: 0.23% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 1c9fca34b9625a67a7f1a03c8604f3df760c6c49, 8053393680d4fa3eb962667d2be95dd39f0940e5, be54a70067c7dbe1381157e8a238fa4b16ea9c05.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 1c9fca34b9625a67a7f1a03c8604f3df760c6c49, 8053393680d4fa3eb962667d2be95dd39f0940e5, be54a70067c7dbe1381157e8a238fa4b16ea9c05 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: arm64: Handle negative S1 walk levels in VNCR TLB size evaluation Computing the effects of a TLB invalidation involves looking at the size of the mapping cached by the TLB. For S1 mappings such as VNCR, this is deducted from the combination of the base granule size and the mapping level. However, this implies that the S1 MMU is *on*. When the MMU is off, we indicate this with the level being set to a "creative" value of -127 (S1_MMU_DISABLED). This ends-up being misinterpreted by pgshift_level_to_ttl() as it doesn't handle negative levels at all (the level is immediately cast to a u8 and only the bottom two bits considered), leading to an invalidation size of 0. Not helpful. Tidy-up pgshift_level_to_ttl() to handle these negative levels, and ttl_to_size() to always return SZ_1G when no valid TTL is present. This allows the removal of open-coded checks for similar situations. Note that the check for a negative value not explicitely checking for S1_MMU_DISABLED is deliberate, so that actual negative levels introduced with LVA2 and D128 can take the same path if we ever support them.

CriticalCVSS 9.3 · v3.1—No exploit Fix available
Published
Sep 16, 2026
Updated
Oct 19, 2026
EPSS
0.2% · 13th percentile
CWE
—

Report tools

JSON

Action score

37

Monitor

Low priority for now.

CVSS
37 / 40 · 9.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CNA vs NVD score

NVD
—
CNA · Linux
9.3
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.

Follow CVE-2026-89775

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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.

We use this product, ask for help

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

    • 6.16affected
    • 7270cc9157f474dfc46750a34c9d7defc686b2eb and later · before be54a70067c7dbe1381157e8a238fa4b16ea9c05affected · git
    • 7270cc9157f474dfc46750a34c9d7defc686b2eb and later · before 1c9fca34b9625a67a7f1a03c8604f3df760c6c49affected · git
    • 7270cc9157f474dfc46750a34c9d7defc686b2eb and later · before 8053393680d4fa3eb962667d2be95dd39f0940e5affected · git
    • before 6.16not affected · semver
    • 6.18.51 and later · up to and including 6.18.*not affected · semver
    • 7.2.5 and later · up to and including 7.2.*not affected · semver
    • 7.3 and laternot affected · original_commit_for_fix

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.61.1.el10_26.12.0-211.61.1.el10_2

+96

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-2026-89773Sep 11, 2026 · drm/amd/display: Skip Update HDCP Config In Transition State
    0Monitor
  • ← EarlierCVE-2026-89774Sep 16, 2026 · Bluetooth: SCO: hold sk properly in sco_conn_ready
    35Monitor
  • Later →CVE-2026-89776Sep 16, 2026 · vxlan: vnifilter: enforce exact length of GROUP/GROUP6 attributes
    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 Linux1c9fca34b9625a67a7f1a03c8604f3df760c6c49Vendor (CNA)
Linux Linux8053393680d4fa3eb962667d2be95dd39f0940e5Vendor (CNA)
Linux Linuxbe54a70067c7dbe1381157e8a238fa4b16ea9c05Vendor (CNA)
almalinux:kernel6.12.0-211.61.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k6.12.0-211.61.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-core6.12.0-211.61.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug6.12.0-211.61.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-core6.12.0-211.61.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel6.12.0-211.61.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched6.12.0-211.61.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules6.12.0-211.61.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-core6.12.0-211.61.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra6.12.0-211.61.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel6.12.0-211.61.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel-matched6.12.0-211.61.1.el10_2 · AlmaLinux:10Package registry (OSV)
debian:linux7.2.6-1 · Debian:14Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-211.61.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-211.61.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-211.61.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-211.61.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-211.61.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-211.61.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-debuginfo0:6.12.0-211.61.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-devel0:6.12.0-211.61.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-devel-matched0:6.12.0-211.61.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debuginfo0:6.12.0-211.61.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debuginfo-common-aarch640:6.12.0-211.61.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debuginfo-common-ppc64le0:6.12.0-211.61.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
rocky linux:kernel0:6.12.0-211.61.1.el10_2 · Rocky Linux:10Package 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.

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.
  • No account or password is required.
  • 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
None
User interaction
None
Scope
Changed
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

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 (3 more)

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

All records