# platform/x86: ISST: Validate logical CPU id and clos id

CVE record · `CVE-2026-89438`

- **Identifiers:** `CVE-2026-89438`
- **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, 19:43 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: `12a7d2cb811dd8a884dea088a2701fcb8d00136e to before 0d601126c7afda9bb94dfecc8b2c0a16f20d76cb` (git)
  - affected: `12a7d2cb811dd8a884dea088a2701fcb8d00136e to before c9ee2770eb95ba316a56d776b2b66666b70c194b` (git)
  - affected: `12a7d2cb811dd8a884dea088a2701fcb8d00136e to before 5b032e1dda486ca41d10536bd195bd8a559af1e2` (git)
  - affected: `12a7d2cb811dd8a884dea088a2701fcb8d00136e to before 82d4afadb02fb4d7d7bb9230900904c10e49ec87` (git)
  - affected: `12a7d2cb811dd8a884dea088a2701fcb8d00136e to before 124e2dbabe460c2a6e7440f4ad8af560131295c9` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `6.4`
  - unaffected: `before 6.4` (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:** 0.0021, the 10th 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-2026-89438](https://www.cve.org/CVERecord?id=CVE-2026-89438)
- [NVD: CVE-2026-89438](https://nvd.nist.gov/vuln/detail/CVE-2026-89438)

### References from the CNA

- <https://git.kernel.org/stable/c/0d601126c7afda9bb94dfecc8b2c0a16f20d76cb>
- <https://git.kernel.org/stable/c/c9ee2770eb95ba316a56d776b2b66666b70c194b>
- <https://git.kernel.org/stable/c/5b032e1dda486ca41d10536bd195bd8a559af1e2>
- <https://git.kernel.org/stable/c/82d4afadb02fb4d7d7bb9230900904c10e49ec87>
- <https://git.kernel.org/stable/c/124e2dbabe460c2a6e7440f4ad8af560131295c9>

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-2026-89438>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89438/>. Everything for agents: <https://agentprime.io/llms.txt>.