# x86/tdx: Fix off-by-one in port I/O handling

CVE record · `CVE-2026-89751`

- **Identifiers:** `CVE-2026-89751`
- **State:** Confirmed
- **Severity:** No CVSS score
- **Critical:** No
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 11 Sept 2026
- **Updated:** 19 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 11 Sept 2026, 19:46 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.

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `03149948832a078f759022ed5b92e722d8d23c26 to before c6875423ad849ac234ab9812eb72f37ff8a490b4` (git)
  - affected: `03149948832a078f759022ed5b92e722d8d23c26 to before 220011fe95fc78b2bc2d7d43893bc73957a5c811` (git)
  - affected: `03149948832a078f759022ed5b92e722d8d23c26 to before 222b7005e4519f633b4cd666226256abbab46a1a` (git)
  - affected: `03149948832a078f759022ed5b92e722d8d23c26 to before c4a22154870813d10aa0b4c734a574c726f9d4b0` (git)
  - affected: `03149948832a078f759022ed5b92e722d8d23c26 to before bb45f705c4440dd3c689328319b88dd28770bbb8` (git)
  - affected: `03149948832a078f759022ed5b92e722d8d23c26 to before 0f63e656b1c679d32ac595de29d10c03efca6a25` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `5.19`
  - unaffected: `before 5.19` (semver)
  - unaffected: `6.1.188 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.157 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.109 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.50 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.4 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

No source has published a CVSS score for this record yet.

- **CISA KEV:** Not listed.
- **EPSS:** 0.0017, the 6th 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 11 Sept 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-89751](https://www.cve.org/CVERecord?id=CVE-2026-89751)
- [NVD: CVE-2026-89751](https://nvd.nist.gov/vuln/detail/CVE-2026-89751)

### References from the CNA

- <https://git.kernel.org/stable/c/c6875423ad849ac234ab9812eb72f37ff8a490b4>
- <https://git.kernel.org/stable/c/220011fe95fc78b2bc2d7d43893bc73957a5c811>
- <https://git.kernel.org/stable/c/222b7005e4519f633b4cd666226256abbab46a1a>
- <https://git.kernel.org/stable/c/c4a22154870813d10aa0b4c734a574c726f9d4b0>
- <https://git.kernel.org/stable/c/bb45f705c4440dd3c689328319b88dd28770bbb8>
- <https://git.kernel.org/stable/c/0f63e656b1c679d32ac595de29d10c03efca6a25>

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-2026-89751>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89751/>. Everything for agents: <https://agentprime.io/llms.txt>.