# CVE-2026-102702: Arm: multiple issues with GNTTABOP_cache_flush

> A guest can corrupt read-only granted memory or crash the hypervisor via GNTTABOP_cache_flush due to missing restrictions and integer underflow.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Oct 2026
- **Updated:** 20 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-102702, GHSA-p4h6-6vf5-jwcw, UBUNTU-CVE-2026-102702

## What is CVE-2026-102702?

CVE-2026-102702 is a high-severity vulnerability in Xen, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

[This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]

1) XSA-437 (CVE-2023-34321) addressed issues with overflows in
   calculations involved in guests flushing caches through
   GNTTABOP_cache_flush.  Unfortunately the fix there introduced a
   calculation which may underflow, resulting in a loop which would - at
   least on 64-bit Arm - take excessively long, and which would likely
   eventually crash the hypervisor.

   This is CVE-2026-102699.

2) GNTTABOP_cache_flush may be issued on memory mapped from another
   domain using the grant table interface.  However there was no
   restriction to disallow the use of invalidate-without-clean against
   read-only grant mappings, which may corrupt the granted memory.

   This is CVE-2026-102702.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound))

## Which versions are affected by CVE-2026-102702?


## How do I fix CVE-2026-102702?

Apply the vendor's patch.

## Is CVE-2026-102702 being exploited?

There is no known exploitation of CVE-2026-102702 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-102702 and fix it if it is affected.

What it is: CVE-2026-102702 is a high-severity vulnerability in Xen, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-102702 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-2026-102702/ (Markdown: https://insights.sbomify.com/CVE-2026-102702/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-102702
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-102702
- OSV: https://osv.dev/vulnerability/CVE-2026-102702

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-102702/
Summaries are generated and may contain mistakes; the official description above is the record.