# CVE-2026-79610: grant-table: double version change race

> A race condition in Xen grant table version changes can lead to stale pointers, potentially allowing code execution or privilege escalation.

- **Severity:** High 8.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/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-2026-79610, DEBIAN-CVE-2026-79610, GHSA-mm4r-fcq9-pfr4, UBUNTU-CVE-2026-79610

## What is CVE-2026-79610?

CVE-2026-79610 is a high-severity 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

XSA-501 was about issues with v1 -> v2 and v2 -> v1 changes racing certain
other grant table operations.  Sadly a v2 -> v1 -> v2 change has yet
another effect which wasn't accounted for: During the first change, status
pages would be freed.  During the second change they would be allocated
again.  Hence across the full pair of change the addresses of the status
pages may change, rendering stale previously calculated pointers into the
status array.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-79610?


## How do I fix CVE-2026-79610?

Apply the vendor's patch.

## Is CVE-2026-79610 being exploited?

There is no known exploitation of CVE-2026-79610 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-79610 and fix it if it is affected.

What it is: CVE-2026-79610 is a high-severity 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-2026-79610 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-2026-79610/ (Markdown: https://insights.sbomify.com/CVE-2026-79610/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-79610
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-79610
- OSV: https://osv.dev/vulnerability/CVE-2026-79610

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-79610/
Summaries are generated and may contain mistakes; the official description above is the record.