# hugetlb: only adjust reservation during unmapping if mapcount is 0

CVE record · `CVE-2026-89593`

- **Identifiers:** `CVE-2026-89593`
- **State:** Confirmed
- **Severity:** CVSS 7.1 High
- **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, 19:44 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: `df7a6d1f64056aec572162c5d35ed9ff86ece6f3 to before b0b1b9ca80b795ed2223e76dd787db7067121fb9` (git)
  - affected: `df7a6d1f64056aec572162c5d35ed9ff86ece6f3 to before a3c65af20cceb7f997847727636b4017326f845d` (git)
  - affected: `df7a6d1f64056aec572162c5d35ed9ff86ece6f3 to before 0f001491e5a2ec69aa9d5dd6b799e5742245f9ea` (git)
  - affected: `df7a6d1f64056aec572162c5d35ed9ff86ece6f3 to before 5120b1e048d48596ffaec1a8412012a91adba73b` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `6.9`
  - unaffected: `before 6.9` (semver)
  - unaffected: `6.12.110 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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0013, the 2nd 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-2026-89593](https://www.cve.org/CVERecord?id=CVE-2026-89593)
- [NVD: CVE-2026-89593](https://nvd.nist.gov/vuln/detail/CVE-2026-89593)

### References from the CNA

- <https://git.kernel.org/stable/c/b0b1b9ca80b795ed2223e76dd787db7067121fb9>
- <https://git.kernel.org/stable/c/a3c65af20cceb7f997847727636b4017326f845d>
- <https://git.kernel.org/stable/c/0f001491e5a2ec69aa9d5dd6b799e5742245f9ea>
- <https://git.kernel.org/stable/c/5120b1e048d48596ffaec1a8412012a91adba73b>

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-2026-89593>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89593/>. Everything for agents: <https://agentprime.io/llms.txt>.