# CVE-2026-102700: gnttab: cache-flush handling may cause page reference leak

> A page reference leak in Xen's grant table cache flush handling can lead to resource exhaustion and denial of service.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Oct 2026
- **Updated:** 20 Oct 2026
- **Also known as:** ALPINE-CVE-2026-102700, DEBIAN-CVE-2026-102700, GHSA-hwfh-h726-49f6, UBUNTU-CVE-2026-102700

## What is CVE-2026-102700?

CVE-2026-102700 is a medium-severity denial of service vulnerability in Xen, published on 13 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

With its original introduction, GNTTAB_cache_flush was made available
uniformly.  XSA-232 (CVE-2017-14318) then covered an omitted NULL
pointer check, yet the addition of that check failed to adjust the
subsequent error path.  That error path fails to drop a page reference in
case the specified page is owned by a special system domain (DOM_IO and
DOM_COW are system domains which can have memory pages assigned to them.)

Weakness: CWE-404 (Improper Resource Shutdown or Release)

## Which versions are affected by CVE-2026-102700?


## How do I fix CVE-2026-102700?

Apply the vendor's patch.

## Is CVE-2026-102700 being exploited?

There is no known exploitation of CVE-2026-102700 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-102700 and fix it if it is affected.

What it is: CVE-2026-102700 is a medium-severity denial of service vulnerability in Xen, published on 13 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-102700 in the wild and no public exploit code.

Affected product: Xen. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-102700/ (Markdown: https://insights.sbomify.com/CVE-2026-102700/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-102700
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-102700
- OSV: https://osv.dev/vulnerability/CVE-2026-102700

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-102700/
Summaries are generated and may contain mistakes; the official description above is the record.