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

CVE record · `CVE-2026-89775`

- **Identifiers:** `CVE-2026-89775`
- **State:** Confirmed
- **Severity:** CVSS 9.3 Critical
- **Critical:** Yes: CVSS 9+
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 16 Sept 2026
- **Updated:** 19 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 16 Sept 2026, 08:39 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Critical

Critical, because:

- CVSS score 9.3: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `7270cc9157f474dfc46750a34c9d7defc686b2eb to before be54a70067c7dbe1381157e8a238fa4b16ea9c05` (git)
  - affected: `7270cc9157f474dfc46750a34c9d7defc686b2eb to before 1c9fca34b9625a67a7f1a03c8604f3df760c6c49` (git)
  - affected: `7270cc9157f474dfc46750a34c9d7defc686b2eb to before 8053393680d4fa3eb962667d2be95dd39f0940e5` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `6.16`
  - unaffected: `before 6.16` (semver)
  - unaffected: `6.18.51 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.5 to 7.2.*, inclusive` (semver)
  - unaffected: `7.3 to *, inclusive` (original_commit_for_fix)
  - Other versions: affected

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 9.3 Critical, CVSS 3.1: `CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`, from CNA (Linux)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0024, the 14th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 16 Sept 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-89775](https://www.cve.org/CVERecord?id=CVE-2026-89775)
- [NVD: CVE-2026-89775](https://nvd.nist.gov/vuln/detail/CVE-2026-89775)

### References from the CNA

- <https://git.kernel.org/stable/c/be54a70067c7dbe1381157e8a238fa4b16ea9c05>
- <https://git.kernel.org/stable/c/1c9fca34b9625a67a7f1a03c8604f3df760c6c49>
- <https://git.kernel.org/stable/c/8053393680d4fa3eb962667d2be95dd39f0940e5>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2026-89775>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89775/>. Everything for agents: <https://agentprime.io/llms.txt>.