# CVE-2025-68760: iommu/amd: Fix potential out-of-bounds read in iommu_mmio_show

> A local attacker with high privileges can trigger an out-of-bounds read in the AMD IOMMU driver, potentially disclosing sensitive kernel memory.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Jan 2026
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-68760, DEBIAN-CVE-2025-68760, GHSA-34rq-jg85-wh39, UBUNTU-CVE-2025-68760

## What is CVE-2025-68760?

CVE-2025-68760 is a vulnerability in Linux, published on 5 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

iommu/amd: Fix potential out-of-bounds read in iommu_mmio_show

In iommu_mmio_write(), it validates the user-provided offset with the
check: `iommu->dbg_mmio_offset > iommu->mmio_phys_end - 4`.
This assumes a 4-byte access. However, the corresponding
show handler, iommu_mmio_show(), uses readq() to perform an 8-byte
(64-bit) read.

If a user provides an offset equal to `mmio_phys_end - 4`, the check
passes, and will lead to a 4-byte out-of-bounds read.

Fix this by adjusting the boundary check to use sizeof(u64), which
corresponds to the size of the readq() operation.

## Which versions are affected by CVE-2025-68760?


## How do I fix CVE-2025-68760?

Apply the vendor's patch.

## Is CVE-2025-68760 being exploited?

There is no known exploitation of CVE-2025-68760 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68760 and fix it if it is affected.

What it is: CVE-2025-68760 is a vulnerability in Linux, published on 5 Jan 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-2025-68760 in the wild and no public exploit code.

Affected product: Linux. 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-2025-68760/ (Markdown: https://insights.sbomify.com/CVE-2025-68760/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68760
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68760
- OSV: https://osv.dev/vulnerability/CVE-2025-68760

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68760/
Summaries are generated and may contain mistakes; the official description above is the record.